1
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Liu R, Wang W, Cui X. Quartet Superfluid in Two-Dimensional Mass-Imbalanced Fermi Mixtures. PHYSICAL REVIEW LETTERS 2023; 131:193401. [PMID: 38000427 DOI: 10.1103/physrevlett.131.193401] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2023] [Revised: 09/25/2023] [Accepted: 10/19/2023] [Indexed: 11/26/2023]
Abstract
Quartet superfluid (QSF) is a distinct type of fermion superfluidity that exhibits high-order correlation beyond the conventional BCS pairing paradigm. In this Letter, we report the emergent QSF in 2D mass-imbalanced Fermi mixtures with two-body contact interactions. This is facilitated by the formation of a quartet bound state in vacuum that consists of a light atom and three heavy fermions. For an optimized heavy-light number ratio 3:1, we identify QSF as the ground state in a considerable parameter regime of mass imbalance and 2D coupling strength. Its unique high-order correlation can be manifested in the momentum-space crystallization of a pairing field and density distribution of heavy fermions. Our results can be readily detected in Fermi-Fermi mixtures nowadays realized in cold atoms laboratories, and meanwhile shed light on exotic superfluidity in a broad context of mass-imbalanced fermion mixtures.
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Affiliation(s)
- Ruijin Liu
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Wei Wang
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xiaoling Cui
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
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2
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Chen ZB, Li JL, Cong SL. High-partial-wave separable potential method for investigating Feshbach resonances of ultracold atoms. Chem Phys Lett 2022. [DOI: 10.1016/j.cplett.2022.140125] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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3
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Sudden quench of harmonically trapped mass-imbalanced fermions. Sci Rep 2022; 12:19710. [PMID: 36385321 PMCID: PMC9668996 DOI: 10.1038/s41598-022-24228-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Accepted: 11/11/2022] [Indexed: 11/17/2022] Open
Abstract
Dynamical properties of two-component mass-imbalanced few-fermion systems confined in a one-dimensional harmonic trap following a sudden quench of interactions are studied. It is assumed that initially the system is prepared in the non-interacting ground state and then, after a sudden quench of interactions, the unitary evolution is governed by interacting many-body Hamiltonian. By careful analysis of the evolution of the Loschmidt echo, density distributions of the components, and entanglement entropy between them, the role of mass imbalance and particle number imbalance on the system's evolution stability are investigated. All the quantities studied manifest a dramatic dependence on the number of heavy and lighter fermions in each component at a given quench strength. The results may have implications for upcoming experiments on fermionic mixtures with a well-defined and small number of particles.
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4
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Ji Y, Schumacher GL, Assumpção GGT, Chen J, Mäkinen JT, Vivanco FJ, Navon N. Stability of the Repulsive Fermi Gas with Contact Interactions. PHYSICAL REVIEW LETTERS 2022; 129:203402. [PMID: 36462022 DOI: 10.1103/physrevlett.129.203402] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Accepted: 08/30/2022] [Indexed: 06/17/2023]
Abstract
We report the creation and the study of the stability of a repulsive quasihomogeneous spin-1/2 Fermi gas with contact interactions. For the range of scattering lengths a explored, the dominant mechanism of decay is a universal three-body recombination toward a Feshbach bound state. We observe that the recombination coefficient K_{3}∝ε_{kin}a^{6}, where the first factor, the average kinetic energy per particle ε_{kin}, arises from a three-body threshold law, and the second one from the universality of recombination. Both scaling laws are consequences of Pauli blocking effects in three-body collisions involving two identical fermions. As a result of the interplay between Fermi statistics and the momentum dependence of the recombination process, the system exhibits nontrivial temperature dynamics during recombination, alternatively heating or cooling depending on its initial quantum degeneracy. The measurement of K_{3} provides an upper bound for the interaction strength achievable in equilibrium for a uniform repulsive Fermi gas.
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Affiliation(s)
- Yunpeng Ji
- Department of Physics, Yale University, New Haven, Connecticut 06520, USA
| | - Grant L Schumacher
- Department of Physics, Yale University, New Haven, Connecticut 06520, USA
| | | | - Jianyi Chen
- Department of Physics, Yale University, New Haven, Connecticut 06520, USA
| | - Jere T Mäkinen
- Department of Physics, Yale University, New Haven, Connecticut 06520, USA
- Yale Quantum Institute, Yale University, New Haven, Connecticut 06520, USA
| | - Franklin J Vivanco
- Department of Physics, Yale University, New Haven, Connecticut 06520, USA
| | - Nir Navon
- Department of Physics, Yale University, New Haven, Connecticut 06520, USA
- Yale Quantum Institute, Yale University, New Haven, Connecticut 06520, USA
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5
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Ciamei A, Finelli S, Trenkwalder A, Inguscio M, Simoni A, Zaccanti M. Exploring Ultracold Collisions in ^{6}Li-^{53}Cr Fermi Mixtures: Feshbach Resonances and Scattering Properties of a Novel Alkali-Transition Metal System. PHYSICAL REVIEW LETTERS 2022; 129:093402. [PMID: 36083677 DOI: 10.1103/physrevlett.129.093402] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Revised: 05/12/2022] [Accepted: 07/21/2022] [Indexed: 06/15/2023]
Abstract
We investigate ultracold collisions in a novel mixture of ^{6}Li and ^{53}Cr fermionic atoms, discovering more than 50 interspecies Feshbach resonances via loss spectroscopy. Building a full coupled-channel model, we unambiguously characterize the ^{6}Li-^{53}Cr scattering properties and yield predictions for other isotopic pairs. In particular, we identify various Feshbach resonances that enable the controlled tuning of elastic s- and p-wave ^{6}Li-^{53}Cr interactions. Our studies thus make lithium-chromium mixtures emerge as optimally suited platforms for the experimental search of elusive few- and many-body regimes of highly correlated fermionic matter, and for the realization of a new class of ultracold polar molecules possessing both electric and magnetic dipole moments.
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Affiliation(s)
- A Ciamei
- Istituto Nazionale di Ottica del Consiglio Nazionale delle Ricerche (CNR-INO), 50019 Sesto Fiorentino, Italy
- European Laboratory for Non-Linear Spectroscopy (LENS), Università di Firenze, 50019 Sesto Fiorentino, Italy
| | - S Finelli
- Istituto Nazionale di Ottica del Consiglio Nazionale delle Ricerche (CNR-INO), 50019 Sesto Fiorentino, Italy
- European Laboratory for Non-Linear Spectroscopy (LENS), Università di Firenze, 50019 Sesto Fiorentino, Italy
| | - A Trenkwalder
- Istituto Nazionale di Ottica del Consiglio Nazionale delle Ricerche (CNR-INO), 50019 Sesto Fiorentino, Italy
- European Laboratory for Non-Linear Spectroscopy (LENS), Università di Firenze, 50019 Sesto Fiorentino, Italy
| | - M Inguscio
- Istituto Nazionale di Ottica del Consiglio Nazionale delle Ricerche (CNR-INO), 50019 Sesto Fiorentino, Italy
- European Laboratory for Non-Linear Spectroscopy (LENS), Università di Firenze, 50019 Sesto Fiorentino, Italy
- Department of Engineering, Campus Bio-Medico University of Rome, 00128 Rome, Italy
| | - A Simoni
- Univ Rennes, CNRS, IPR (Institut de Physique de Rennes)-UMR 6251, F-35000 Rennes, France
| | - M Zaccanti
- Istituto Nazionale di Ottica del Consiglio Nazionale delle Ricerche (CNR-INO), 50019 Sesto Fiorentino, Italy
- European Laboratory for Non-Linear Spectroscopy (LENS), Università di Firenze, 50019 Sesto Fiorentino, Italy
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6
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Liu R, Peng C, Cui X. Universal Tetramer and Pentamer Bound States in Two-Dimensional Fermionic Mixtures. PHYSICAL REVIEW LETTERS 2022; 129:073401. [PMID: 36018681 DOI: 10.1103/physrevlett.129.073401] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2022] [Revised: 05/03/2022] [Accepted: 07/18/2022] [Indexed: 06/15/2023]
Abstract
We study the emergence of universal tetramer and pentamer bound states in the two-dimensional (N+1) system, which consists of N identical heavy fermions interacting with a light atom. We show that the critical heavy-light mass ratio to support a (3+1) tetramer below the trimer threshold is 3.38, and to support a (4+1) pentamer below the tetramer threshold is 5.14. While the ground state tetramer and pentamer are both with zero total angular momentum, they exhibit very different density distributions and correlations in momentum space, due to their distinct angular momentum decompositions in the dimer-fermion frame. These universal bound states can be accessible by a number of Fermi-Fermi mixtures now realized in cold atoms laboratories, which also suggest novel few-body correlations dominant in their corresponding many-body systems.
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Affiliation(s)
- Ruijin Liu
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Cheng Peng
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xiaoling Cui
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, China
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7
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Giri MK, Mondal S, Das BP, Mishra T. Signatures of Nontrivial Pairing in the Quantum Walk of Two-Component Bosons. PHYSICAL REVIEW LETTERS 2022; 129:050601. [PMID: 35960573 DOI: 10.1103/physrevlett.129.050601] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/12/2021] [Revised: 01/16/2022] [Accepted: 07/08/2022] [Indexed: 06/15/2023]
Abstract
Nearest neighbor bosons possessing only on-site interactions do not form on-site bound pairs in their quantum walk due to fermionization. We obtain signatures of nontrivial on-site pairing in the quantum walk of strongly interacting two component bosons in a one dimensional lattice. By considering an initial state with particles from different components located at the nearest-neighbor sites in the central region of the lattice, we show that in the dynamical evolution of the system, competing intra- and intercomponent on-site repulsion leads to the formation of on-site intercomponent bound states. We find that when the total number of particles is three, an intercomponent pair is favored in the limit of equal intra- and intercomponent interaction strengths. However, when two bosons from each species are considered, intercomponent pairs and trimer are favored depending on the ratios of the intra- and intercomponent interactions. In both cases, we find that the quantum walks exhibit a reentrant behavior as a function of intercomponent interaction.
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Affiliation(s)
- Mrinal Kanti Giri
- Department of Physics, Indian Institute of Technology, Guwahati-781039, India
| | - Suman Mondal
- Department of Physics, Indian Institute of Technology, Guwahati-781039, India
| | - B P Das
- Centre for Quantum Engineering Research and Education, TCG Centres for Research and Education in Science and Technology, Sector V, Salt Lake, Kolkata 70091, India
- Department of Physics, School of Science, Tokyo Institute of Technology, 2-1-2-1-H86, Ookayama, Meguro-ku, Tokyo 152-8550, Japan
| | - Tapan Mishra
- Department of Physics, Indian Institute of Technology, Guwahati-781039, India
- Centre for Quantum Engineering Research and Education, TCG Centres for Research and Education in Science and Technology, Sector V, Salt Lake, Kolkata 70091, India
- National Institute of Science Education and Research, HBNI, Jatni 752050, India
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8
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Weckesser P, Thielemann F, Wiater D, Wojciechowska A, Karpa L, Jachymski K, Tomza M, Walker T, Schaetz T. Observation of Feshbach resonances between a single ion and ultracold atoms. Nature 2021; 600:429-433. [PMID: 34912091 DOI: 10.1038/s41586-021-04112-y] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2021] [Accepted: 10/08/2021] [Indexed: 11/09/2022]
Abstract
The control of physical systems and their dynamics on the level of individual quanta underpins both fundamental science and quantum technologies. Trapped atomic and molecular systems, neutral1 and charged2, are at the forefront of quantum science. Their extraordinary level of control is evidenced by numerous applications in quantum information processing3,4 and quantum metrology5,6. Studies of the long-range interactions between these systems when combined in a hybrid atom-ion trap7,8 have led to landmark results9-19. However, reaching the ultracold regime-where quantum mechanics dominates the interaction, for example, giving access to controllable scattering resonances20,21-has so far been elusive. Here we demonstrate Feshbach resonances between ions and atoms, using magnetically tunable interactions between 138Ba+ ions and 6Li atoms. We tune the experimental parameters to probe different interaction processes-first, enhancing three-body reactions22,23 and the related losses to identify the resonances and then making two-body interactions dominant to investigate the ion's sympathetic cooling19 in the ultracold atomic bath. Our results provide deeper insights into atom-ion interactions, giving access to complex many-body systems24-27 and applications in experimental quantum simulation28-30.
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Affiliation(s)
- Pascal Weckesser
- Albert-Ludwigs-Universität Freiburg, Physikalisches Institut, Freiburg, Germany.
| | - Fabian Thielemann
- Albert-Ludwigs-Universität Freiburg, Physikalisches Institut, Freiburg, Germany
| | - Dariusz Wiater
- Faculty of Physics, University of Warsaw, Warsaw, Poland
| | | | - Leon Karpa
- Albert-Ludwigs-Universität Freiburg, Physikalisches Institut, Freiburg, Germany.,Leibniz University Hannover, Institute of Quantum Optics, Hannover, Germany
| | | | - Michał Tomza
- Faculty of Physics, University of Warsaw, Warsaw, Poland
| | - Thomas Walker
- Albert-Ludwigs-Universität Freiburg, Physikalisches Institut, Freiburg, Germany.,EUCOR Centre for Quantum Science and Quantum Computing, Albert-Ludwigs-Universität Freiburg, Freiburg, Germany
| | - Tobias Schaetz
- Albert-Ludwigs-Universität Freiburg, Physikalisches Institut, Freiburg, Germany.,EUCOR Centre for Quantum Science and Quantum Computing, Albert-Ludwigs-Universität Freiburg, Freiburg, Germany
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9
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Giri MK, Mondal S, Das BP, Mishra T. Two component quantum walk in one-dimensional lattice with hopping imbalance. Sci Rep 2021; 11:22056. [PMID: 34764349 PMCID: PMC8585883 DOI: 10.1038/s41598-021-01230-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2021] [Accepted: 10/12/2021] [Indexed: 11/23/2022] Open
Abstract
We investigate the two-component quantum walk in one-dimensional lattice. We show that the inter-component interaction strength together with the hopping imbalance between the components exhibit distinct features in the quantum walk for different initial states. When the walkers are initially on the same site, both the slow and fast particles perform independent particle quantum walks when the interaction between them is weak. However, stronger inter-particle interactions result in quantum walks by the repulsively bound pair formed between the two particles. For different initial states when the walkers are on different sites initially, the quantum walk performed by the slow particle is almost independent of that of the fast particle, which exhibits reflected and transmitted components across the particle with large hopping strength for weak interactions. Beyond a critical value of the interaction strength, the wave function of the fast particle ceases to penetrate through the slow particle signalling a spatial phase separation. However, when the two particles are initially at the two opposite edges of the lattice, then the interaction facilitates the complete reflection of both of them from each other. We analyze the above mentioned features by examining various physical quantities such as the on-site density evolution, two-particle correlation functions and transmission coefficients.
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Affiliation(s)
- Mrinal Kanti Giri
- Department of Physics, Indian Institute of Technology, Guwahati, 781039, India
| | - Suman Mondal
- Department of Physics, Indian Institute of Technology, Guwahati, 781039, India
| | - Bhanu Pratap Das
- Centre for Quantum Engineering Research and Education, TCG Centres for Research and Education in Science and Technology, Sector V, Salt Lake, Kolkata, 70091, India. .,Department of Physics, School of Science, Tokyo Institute of Technology, 2-1-2-1-H86 Ookayama Meguro-ku, Tokyo, 152-8550, Japan.
| | - Tapan Mishra
- Department of Physics, Indian Institute of Technology, Guwahati, 781039, India. .,Centre for Quantum Engineering Research and Education, TCG Centres for Research and Education in Science and Technology, Sector V, Salt Lake, Kolkata, 70091, India.
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10
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Karmakar M. Pauli limited d-wave superconductors: quantum breached pair phase and thermal transitions. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2020; 32:405604. [PMID: 32396876 DOI: 10.1088/1361-648x/ab926a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2019] [Accepted: 05/12/2020] [Indexed: 06/11/2023]
Abstract
We report a quantum phase transition in Pauli limited d-wave superconductors and give the mean field estimates of the associated quantum critical point. For a population imbalanced d-wave superconductor a stable ground state phase viz quantum breached pair phase has been identified which comprises of spatial coexistence of gapless superconductivity and nonzero magnetization. Based on the thermodynamic and quasiparticle indicators we for the first time analyze this phase, discuss the thermal behavior of Pauli limited d-wave superconductor, give accurate estimates of the thermal scales associated with such systems and map out the pseudogap regime. Our work shows that while the Pauli limited superconductors are known to exhibit exotic modulated superconducting phase at large imbalance of fermion populations; in the regime of weak imbalance an intriguing phase of competing orders is realized. We have established that rather than the superconducting pairing field, it is the average magnetization of the system that quantifies this quantum phase transition. Given that the existing Pauli limited superconductors possess unconventional pairing state symmetry of the superconducting order, our work promises to open up new avenues in the experimental research of these materials. We have also demonstrated an alternate scenario wherein the quantum breached pair phase is a natural outcome for a d-wave superconductor with unequal effective masses of the fermion species.
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11
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Ravensbergen C, Soave E, Corre V, Kreyer M, Huang B, Kirilov E, Grimm R. Resonantly Interacting Fermi-Fermi Mixture of ^{161}Dy and ^{40}K. PHYSICAL REVIEW LETTERS 2020; 124:203402. [PMID: 32501049 DOI: 10.1103/physrevlett.124.203402] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Revised: 03/12/2020] [Accepted: 05/04/2020] [Indexed: 06/11/2023]
Abstract
We report on the realization of a Fermi-Fermi mixture of ultracold atoms that combines mass imbalance, tunability, and collisional stability. In an optically trapped sample of ^{161}Dy and ^{40}K, we identify a broad Feshbach resonance centered at a magnetic field of 217 G. Hydrodynamic expansion profiles in the resonant interaction regime reveal a bimodal behavior resulting from mass imbalance. Lifetime studies on resonance show a suppression of inelastic few-body processes by orders of magnitude, which we interpret as a consequence of the fermionic nature of our system. The resonant mixture opens up intriguing perspectives for studies on novel states of strongly correlated fermions with mass imbalance.
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Affiliation(s)
- C Ravensbergen
- Institut für Experimentalphysik, Universität Innsbruck, 6020 Innsbruck, Austria
- Institut für Quantenoptik und Quanteninformation (IQOQI), Österreichische Akademie der Wissenschaften, 6020 Innsbruck, Austria
| | - E Soave
- Institut für Experimentalphysik, Universität Innsbruck, 6020 Innsbruck, Austria
| | - V Corre
- Institut für Experimentalphysik, Universität Innsbruck, 6020 Innsbruck, Austria
- Institut für Quantenoptik und Quanteninformation (IQOQI), Österreichische Akademie der Wissenschaften, 6020 Innsbruck, Austria
| | - M Kreyer
- Institut für Experimentalphysik, Universität Innsbruck, 6020 Innsbruck, Austria
| | - B Huang
- Institut für Experimentalphysik, Universität Innsbruck, 6020 Innsbruck, Austria
- Institut für Quantenoptik und Quanteninformation (IQOQI), Österreichische Akademie der Wissenschaften, 6020 Innsbruck, Austria
| | - E Kirilov
- Institut für Experimentalphysik, Universität Innsbruck, 6020 Innsbruck, Austria
| | - R Grimm
- Institut für Experimentalphysik, Universität Innsbruck, 6020 Innsbruck, Austria
- Institut für Quantenoptik und Quanteninformation (IQOQI), Österreichische Akademie der Wissenschaften, 6020 Innsbruck, Austria
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12
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Yang A, Botsi S, Kumar S, Pal SB, Lam MM, Čepaitė I, Laugharn A, Dieckmann K. Singlet Pathway to the Ground State of Ultracold Polar Molecules. PHYSICAL REVIEW LETTERS 2020; 124:133203. [PMID: 32302184 DOI: 10.1103/physrevlett.124.133203] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2019] [Accepted: 03/09/2020] [Indexed: 06/11/2023]
Abstract
Starting from weakly bound Feshbach molecules, we demonstrate a two-photon pathway to the dipolar ground state of bi-alkali molecules that involves only singlet-to-singlet optical transitions. This pathway eliminates the search for a suitable intermediate state with sufficient singlet-triplet mixing and the exploration of its hyperfine structure, as is typical for pathways starting from triplet dominated Feshbach molecules. By selecting a Feshbach state with a stretched singlet hyperfine component and controlling the laser polarizations, we assure coupling to only single hyperfine components of the A^{1}Σ^{+} excited potential and the X^{1}Σ^{+} rovibrational ground state. In this way an ideal three level system is established, even if the hyperfine structure is not resolved. We demonstrate this pathway with ^{6}Li^{40}K molecules, and discuss its application to other important molecular species.
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Affiliation(s)
- A Yang
- Centre for Quantum Technologies (CQT), 3 Science Drive 2, Singapore 117543, Singapore
| | - S Botsi
- Centre for Quantum Technologies (CQT), 3 Science Drive 2, Singapore 117543, Singapore
| | - S Kumar
- Centre for Quantum Technologies (CQT), 3 Science Drive 2, Singapore 117543, Singapore
| | - S B Pal
- Centre for Quantum Technologies (CQT), 3 Science Drive 2, Singapore 117543, Singapore
| | - M M Lam
- Centre for Quantum Technologies (CQT), 3 Science Drive 2, Singapore 117543, Singapore
| | - I Čepaitė
- Centre for Quantum Technologies (CQT), 3 Science Drive 2, Singapore 117543, Singapore
| | - A Laugharn
- Centre for Quantum Technologies (CQT), 3 Science Drive 2, Singapore 117543, Singapore
| | - K Dieckmann
- Centre for Quantum Technologies (CQT), 3 Science Drive 2, Singapore 117543, Singapore
- Department of Physics, National University of Singapore, 2 Science Drive 3, Singapore 117542, Singapore
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13
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Sowiński T, Ángel García-March M. One-dimensional mixtures of several ultracold atoms: a review. REPORTS ON PROGRESS IN PHYSICS. PHYSICAL SOCIETY (GREAT BRITAIN) 2019; 82:104401. [PMID: 31404916 DOI: 10.1088/1361-6633/ab3a80] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Recent theoretical and experimental progress on studying one-dimensional systems of bosonic, fermionic, and Bose-Fermi mixtures of a few ultracold atoms confined in traps is reviewed in the broad context of mesoscopic quantum physics. We pay special attention to limiting cases of very strong or very weak interactions and transitions between them. For bosonic mixtures, we describe the developments in systems of three and four atoms as well as different extensions to larger numbers of particles. We also briefly review progress in the case of spinor Bose gases of a few atoms. For fermionic mixtures, we discuss a special role of spin and present a detailed discussion of the two- and three-atom cases. We discuss the advantages and disadvantages of different computation methods applied to systems with intermediate interactions. In the case of very strong repulsion, close to the infinite limit, we discuss approaches based on effective spin chain descriptions. We also report on recent studies on higher-spin mixtures and inter-component attractive forces. For both statistics, we pay particular attention to impurity problems and mass imbalance cases. Finally, we describe the recent advances on trapped Bose-Fermi mixtures, which allow for a theoretical combination of previous concepts, well illustrating the importance of quantum statistics and inter-particle interactions. Lastly, we report on fundamental questions related to the subject which we believe will inspire further theoretical developments and experimental verification.
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Affiliation(s)
- Tomasz Sowiński
- Institute of Physics, Polish Academy of Sciences, Aleja Lotników 32/46, PL-02668 Warsaw, Poland
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14
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Simonelli C, Neri E, Ciamei A, Goti I, Inguscio M, Trenkwalder A, Zaccanti M. Realization of a high power optical trapping setup free from thermal lensing effects. OPTICS EXPRESS 2019; 27:27215-27228. [PMID: 31674587 DOI: 10.1364/oe.27.027215] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2019] [Accepted: 07/01/2019] [Indexed: 06/10/2023]
Abstract
Transmission of high power laser beams through partially absorbing materials modifies the light propagation via a thermally-induced effect known as thermal lensing. This may cause changes in the beam waist position and degrade the beam quality. Here we characterize the effect of thermal lensing associated with the different elements typically employed in an optical trapping setup for cold atoms experiments. We find that the only relevant thermal lens is represented by the TeO2 crystal of the acousto-optic modulator exploited to adjust the laser power on the atomic sample. We then devise a simple and totally passive scheme that enables to realize an inexpensive optical trapping apparatus essentially free from thermal lensing effects.
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15
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Li LH, Li JL, Wang GR, Cong SL. The modulating action of electric field on magnetically tuned Feshbach resonance. J Chem Phys 2019; 150:064310. [DOI: 10.1063/1.5081628] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Li-Hang Li
- School of Physics, Dalian University of Technology, Dalian 116024, China
| | - Jing-Lun Li
- School of Physics, Dalian University of Technology, Dalian 116024, China
| | - Gao-Ren Wang
- School of Physics, Dalian University of Technology, Dalian 116024, China
| | - Shu-Lin Cong
- School of Physics, Dalian University of Technology, Dalian 116024, China
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16
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Li JL, Cong SL. Accurate calculations of weakly bound state energy and scattering length near magnetically tuned Feshbach resonance using the separable potential method. J Chem Phys 2018; 149:154105. [PMID: 30342436 DOI: 10.1063/1.5047586] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
We present a theoretical model for investigating the magnetically tuned Feshbach resonance (MTFR) of alkali metal atoms using the separable potential method (SPM). We discuss the relationship and difference between the SPM and the asymptotic bound state model. To demonstrate the validity of the SPM, we use it to calculate the weakly bound state energy and magnetically tuned scattering length for the 6Li-40K, 7Li2, and 6Li2 systems with narrow and broad Feshbach resonances. The results of the SPM calculations are in good agreement with those of coupled channel calculations and with experimental measurements for all three systems. The SPM, by simplifying the calculation of the two-body MTFR, is expected to simplify numerical computations for three-atom collisions in a magnetic field and the Feshbach-optimized photoassociation process.
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Affiliation(s)
- Jing-Lun Li
- School of Physics, Dalian University of Technology, Dalian 116024, China
| | - Shu-Lin Cong
- School of Physics, Dalian University of Technology, Dalian 116024, China
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17
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Cao L, Bolsinger V, Mistakidis SI, Koutentakis GM, Krönke S, Schurer JM, Schmelcher P. A unified ab initio approach to the correlated quantum dynamics of ultracold fermionic and bosonic mixtures. J Chem Phys 2018; 147:044106. [PMID: 28764383 DOI: 10.1063/1.4993512] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
We extent the recently developed Multi-Layer Multi-Configuration Time-Dependent Hartree method for Bosons for simulating the correlated quantum dynamics of bosonic mixtures to the fermionic sector and establish a unifying approach for the investigation of the correlated quantum dynamics of a mixture of indistinguishable particles, be it fermions or bosons. Relying on a multi-layer wave-function expansion, the resulting Multi-Layer Multi-Configuration Time-Dependent Hartree method for Mixtures (ML-MCTDHX) can be adapted to efficiently resolve system-specific intra- and inter-species correlations. The versatility and efficiency of ML-MCTDHX are demonstrated by applying it to the problem of colliding few-atom mixtures of both Bose-Fermi and Fermi-Fermi types. Thereby, we elucidate the role of correlations in the transmission and reflection properties of the collisional events. In particular, we present examples where the reflection (transmission) at the other atomic species is a correlation-dominated effect, i.e., it is suppressed in the mean-field approximation.
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Affiliation(s)
- L Cao
- Zentrum für Optische Quantentechnologien, Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg, Germany
| | - V Bolsinger
- Zentrum für Optische Quantentechnologien, Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg, Germany
| | - S I Mistakidis
- Zentrum für Optische Quantentechnologien, Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg, Germany
| | - G M Koutentakis
- Zentrum für Optische Quantentechnologien, Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg, Germany
| | - S Krönke
- Zentrum für Optische Quantentechnologien, Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg, Germany
| | - J M Schurer
- Zentrum für Optische Quantentechnologien, Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg, Germany
| | - P Schmelcher
- Zentrum für Optische Quantentechnologien, Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg, Germany
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18
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Kinnunen JJ, Baarsma JE, Martikainen JP, Törmä P. The Fulde-Ferrell-Larkin-Ovchinnikov state for ultracold fermions in lattice and harmonic potentials: a review. REPORTS ON PROGRESS IN PHYSICS. PHYSICAL SOCIETY (GREAT BRITAIN) 2018; 81:046401. [PMID: 29293087 DOI: 10.1088/1361-6633/aaa4ad] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
We review the concepts and the present state of theoretical studies of spin-imbalanced superfluidity, in particular the elusive Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) state, in the context of ultracold quantum gases. The comprehensive presentation of the theoretical basis for the FFLO state that we provide is useful also for research on the interplay between magnetism and superconductivity in other physical systems. We focus on settings that have been predicted to be favourable for the FFLO state, such as optical lattices in various dimensions and spin-orbit coupled systems. These are also the most likely systems for near-future experimental observation of the FFLO state. Theoretical bounds, such as Bloch's and Luttinger's theorems, and experimentally important limitations, such as finite-size effects and trapping potentials, are considered. In addition, we provide a comprehensive review of the various ideas presented for the observation of the FFLO state. We conclude our review with an analysis of the open questions related to the FFLO state, such as its stability, superfluid density, collective modes and extending the FFLO superfluid concept to new types of lattice systems.
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Affiliation(s)
- Jami J Kinnunen
- COMP Center of Excellence, Department of Applied Physics, Aalto University, Fi-00076, Aalto, Finland
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19
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Jasik P, Kozicki J, Kilich T, Sienkiewicz JE, Henriksen NE. Electronic structure and rovibrational predissociation of the 2 1Π state in KLi. Phys Chem Chem Phys 2018; 20:18663-18670. [DOI: 10.1039/c8cp02551g] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Adiabatic potential energy curves of the 31Σ+, 33Σ+, 21Π and 23Π states correlating for large internuclear distance with the K(4s) + Li(2p) atomic asymptote were calculated. Lifetimes of the quasi-bound rovibrational states of the 21Π state were determined by explicit time propagation.
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Affiliation(s)
- P. Jasik
- Faculty of Applied Physics and Mathematics
- Gdańsk University of Technology
- 80-233 Gdańsk
- Poland
| | - J. Kozicki
- Faculty of Civil and Environmental Engineering
- Gdańsk University of Technology
- 80-233 Gdańsk
- Poland
| | - T. Kilich
- Faculty of Applied Physics and Mathematics
- Gdańsk University of Technology
- 80-233 Gdańsk
- Poland
| | - J. E. Sienkiewicz
- Faculty of Applied Physics and Mathematics
- Gdańsk University of Technology
- 80-233 Gdańsk
- Poland
| | - N. E. Henriksen
- Department of Chemistry
- Building 207, Technical University of Denmark
- DK-2800 Kgs. Lyngby
- Denmark
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20
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Ptok A. The influence of the dimensionality of the system on the realization of unconventional Fulde-Ferrell-Larkin-Ovchinnikov pairing in ultra-cold Fermi gases. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2017; 29:475901. [PMID: 29019340 DOI: 10.1088/1361-648x/aa928d] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The recent development of experimental techniques in ultracold atomic Fermi gases is extremely helpful in the progress of the realization of the unconventional Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) superfluid phase in quasi-one dimensional systems (Liao et al 2010 Nature 467 567). Due to a Fermi surface nesting, which is enhanced in 1D, the low-dimensional systems are particularly good candidates to find the FFLO phase stable. We investigate the influence of a dimensional crossover (from one dimension (1D) to two dimensions (2D) or three dimensions (3D)) on the stability of the FFLO state in the spin-imbalanced attractive Hubbard model.
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Affiliation(s)
- Andrzej Ptok
- Institute of Nuclear Physics, Polish Academy of Sciences, ul. E. Radzikowskiego 152, PL-31342 Kraków, Poland. Institute of Physics, Maria Curie-Skłodowska University, Plac M. Skłodowskiej-Curie 1, PL-20031 Lublin, Poland
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21
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Cui Y, Shen C, Deng M, Dong S, Chen C, Lü R, Gao B, Tey MK, You L. Observation of Broad d-Wave Feshbach Resonances with a Triplet Structure. PHYSICAL REVIEW LETTERS 2017; 119:203402. [PMID: 29219388 DOI: 10.1103/physrevlett.119.203402] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2017] [Indexed: 06/07/2023]
Abstract
High partial-wave (l≥2) Feshbach resonance (FR) in an ultracold mixture of ^{85}Rb-^{87}Rb atoms is investigated experimentally aided by a partial-wave insensitive analytic multichannel quantum-defect theory. Two "broad" resonances from coupling between d waves in both the open and closed channels are observed and characterized. One of them shows a fully resolved triplet structure with a splitting ratio well explained by the perturbation to the closed channel due to interatomic spin-spin interaction. These tunable "broad" d-wave resonances, especially the one in the lowest-energy open channel, could find important applications in simulating d-wave coupling dominated many-body systems. In addition, we find that there is generally a time and temperature requirement, associated with tunneling through the angular momentum barrier, to establish and observe resonant coupling in nonzero partial waves.
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Affiliation(s)
- Yue Cui
- State Key Laboratory of Low Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing 100084, China
| | - Chuyang Shen
- State Key Laboratory of Low Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing 100084, China
| | - Min Deng
- State Key Laboratory of Low Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing 100084, China
| | - Shen Dong
- State Key Laboratory of Low Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing 100084, China
| | - Cheng Chen
- State Key Laboratory of Low Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing 100084, China
| | - Rong Lü
- State Key Laboratory of Low Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing 100084, China
- Collaborative Innovation Center of Quantum Matter, Beijing, China
| | - Bo Gao
- Department of Physics and Astronomy, University of Toledo, Mailstop 111, Toledo, Ohio 43606, USA
| | - Meng Khoon Tey
- State Key Laboratory of Low Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing 100084, China
- Collaborative Innovation Center of Quantum Matter, Beijing, China
| | - Li You
- State Key Laboratory of Low Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing 100084, China
- Collaborative Innovation Center of Quantum Matter, Beijing, China
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22
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Vexiau R, Borsalino D, Lepers M, Orbán A, Aymar M, Dulieu O, Bouloufa-Maafa N. Dynamic dipole polarizabilities of heteronuclear alkali dimers: optical response, trapping and control of ultracold molecules. INT REV PHYS CHEM 2017. [DOI: 10.1080/0144235x.2017.1351821] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
- R. Vexiau
- Laboratoire Aimé Cotton, CNRS, Université Paris-Sud, ENS Cachan, Université Paris-Saclay, Orsay Cedex, France
| | - D. Borsalino
- Laboratoire Aimé Cotton, CNRS, Université Paris-Sud, ENS Cachan, Université Paris-Saclay, Orsay Cedex, France
| | - M. Lepers
- Laboratoire Aimé Cotton, CNRS, Université Paris-Sud, ENS Cachan, Université Paris-Saclay, Orsay Cedex, France
| | - A. Orbán
- Laboratoire Aimé Cotton, CNRS, Université Paris-Sud, ENS Cachan, Université Paris-Saclay, Orsay Cedex, France
| | - M. Aymar
- Laboratoire Aimé Cotton, CNRS, Université Paris-Sud, ENS Cachan, Université Paris-Saclay, Orsay Cedex, France
| | - O. Dulieu
- Laboratoire Aimé Cotton, CNRS, Université Paris-Sud, ENS Cachan, Université Paris-Saclay, Orsay Cedex, France
| | - N. Bouloufa-Maafa
- Laboratoire Aimé Cotton, CNRS, Université Paris-Sud, ENS Cachan, Université Paris-Saclay, Orsay Cedex, France
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23
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Krauser JS, Heinze J, Götze S, Langbecker M, Fläschner N, Cook L, Hanna TM, Tiesinga E, Sengstock K, Becker C. Investigation of Feshbach resonances in ultracold 40K spin mixtures. PHYSICAL REVIEW. A 2017; 95:042701. [PMID: 29876533 PMCID: PMC5986192 DOI: 10.1103/physreva.95.042701] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Magnetically tunable Feshbach resonances are an indispensable tool for experiments with atomic quantum gases. We report on 37 thus far unpublished Feshbach resonances and four further probable Feshbach resonances in spin mixtures of ultracold fermionic 40K with temperatures well below 100 nK. In particular, we locate a broad resonance at B = 389.7G with a magnetic width of 26.7 G. Here 1 G = 10-4 T. Furthermore, by exciting low-energy spin waves, we demonstrate a means to precisely determine the zero crossing of the scattering length for this broad Feshbach resonance. Our findings allow for further tunability in experiments with ultracold 40K quantum gases.
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Affiliation(s)
- J. S. Krauser
- Institut für Laser-Physik, Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg, Germany
- Zentrum für Optische Quantentechnologien, Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg, Germany
| | - J. Heinze
- Institut für Laser-Physik, Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg, Germany
- Zentrum für Optische Quantentechnologien, Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg, Germany
| | - S. Götze
- Institut für Laser-Physik, Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg, Germany
| | - M. Langbecker
- Institut für Laser-Physik, Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg, Germany
- Institut für Physik, Johannes Gutenberg Universität Mainz, Staudingerweg 7, 55128 Mainz, Germany
| | - N. Fläschner
- Institut für Laser-Physik, Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg, Germany
| | - L. Cook
- Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT, United Kingdom
| | - T. M. Hanna
- Joint Quantum Institute, National Institute of Standards and Technology and the University of Maryland, Gaithersburg, Maryland 20899, USA
| | - E. Tiesinga
- Joint Quantum Institute, National Institute of Standards and Technology and the University of Maryland, Gaithersburg, Maryland 20899, USA
| | - K. Sengstock
- Institut für Laser-Physik, Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg, Germany
- Zentrum für Optische Quantentechnologien, Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg, Germany
| | - C. Becker
- Institut für Laser-Physik, Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg, Germany
- Zentrum für Optische Quantentechnologien, Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg, Germany
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24
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Wang J, Che Y, Zhang L, Chen Q. Enhancement effect of mass imbalance on Fulde-Ferrell-Larkin-Ovchinnikov type of pairing in Fermi-Fermi mixtures of ultracold quantum gases. Sci Rep 2017; 7:39783. [PMID: 28051145 PMCID: PMC5209654 DOI: 10.1038/srep39783] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2016] [Accepted: 11/28/2016] [Indexed: 11/09/2022] Open
Abstract
Ultracold two-component Fermi gases with a tunable population imbalance have provided an excellent opportunity for studying the exotic Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) states, which have been of great interest in condensed matter physics. However, the FFLO states have not been observed experimentally in Fermi gases in three dimensions (3D), possibly due to their small phase space volume and extremely low temperature required for an equal-mass Fermi gas. Here we explore possible effects of mass imbalance, mainly in a 6Li-40K mixture, on the one-plane-wave FFLO phases for a 3D homogeneous case at the mean-field level. We present various phase diagrams related to the FFLO states at both zero and finite temperatures, throughout the BCS-BEC crossover, and show that a large mass ratio may enhance substantially FFLO type of pairing.
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Affiliation(s)
- Jibiao Wang
- Department of Physics and Zhejiang Institute of Modern Physics, Zhejiang University, Hangzhou, Zhejiang 310027, China
- Synergetic Innovation Center of Quantum Information and Quantum Physics, Hefei, Anhui 230026, China
| | - Yanming Che
- Department of Physics and Zhejiang Institute of Modern Physics, Zhejiang University, Hangzhou, Zhejiang 310027, China
- Synergetic Innovation Center of Quantum Information and Quantum Physics, Hefei, Anhui 230026, China
| | - Leifeng Zhang
- Department of Physics and Zhejiang Institute of Modern Physics, Zhejiang University, Hangzhou, Zhejiang 310027, China
- Synergetic Innovation Center of Quantum Information and Quantum Physics, Hefei, Anhui 230026, China
| | - Qijin Chen
- Department of Physics and Zhejiang Institute of Modern Physics, Zhejiang University, Hangzhou, Zhejiang 310027, China
- Synergetic Innovation Center of Quantum Information and Quantum Physics, Hefei, Anhui 230026, China
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25
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Bowden W, Gunton W, Semczuk M, Dare K, Madison KW. An adaptable dual species effusive source and Zeeman slower design demonstrated with Rb and Li. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2016; 87:043111. [PMID: 27131658 DOI: 10.1063/1.4945567] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
We present a dual-species effusive source and Zeeman slower designed to produce slow atomic beams of two elements with a large mass difference and with very different oven temperature requirements. We demonstrate this design for the case of (6)Li and (85)Rb and achieve magneto-optical trap (MOT) loading rates equivalent to that reported in prior work on dual species (Rb+Li) Zeeman slowers operating at the same oven temperatures. Key design choices, including thermally separating the effusive sources and using a segmented coil design to enable computer control of the magnetic field profile, ensure that the apparatus can be easily modified to slow other atomic species. By performing the final slowing using the quadrupole magnetic field of the MOT, we are able to shorten our Zeeman slower length making for a more compact system without compromising performance. We outline the construction and analyze the emission properties of our effusive sources. We also verify the performance of the source and slower, and we observe sequential loading rates of 12 × 10(8) atoms/s for a Rb oven temperature of 140 °C and 1.1 × 10(8) atoms/s for a Li reservoir at 460 °C, corresponding to reservoir lifetimes for continuous operation of 10 and 4 years, respectively.
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Affiliation(s)
- William Bowden
- The Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
| | - Will Gunton
- The Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
| | - Mariusz Semczuk
- The Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
| | - Kahan Dare
- The Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
| | - Kirk W Madison
- The Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
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26
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Frisch A, Mark M, Aikawa K, Baier S, Grimm R, Petrov A, Kotochigova S, Quéméner G, Lepers M, Dulieu O, Ferlaino F. Ultracold Dipolar Molecules Composed of Strongly Magnetic Atoms. PHYSICAL REVIEW LETTERS 2015; 115:203201. [PMID: 26613437 DOI: 10.1103/physrevlett.115.203201] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2015] [Indexed: 06/05/2023]
Abstract
In a combined experimental and theoretical effort, we demonstrate a novel type of dipolar system made of ultracold bosonic dipolar molecules with large magnetic dipole moments. Our dipolar molecules are formed in weakly bound Feshbach molecular states from a sample of strongly magnetic bosonic erbium atoms. We show that the ultracold magnetic molecules can carry very large dipole moments and we demonstrate how to create and characterize them, and how to change their orientation. Finally, we confirm that the relaxation rates of molecules in a quasi-two-dimensional geometry can be reduced by using the anisotropy of the dipole-dipole interaction and that this reduction follows a universal dipolar behavior.
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Affiliation(s)
- A Frisch
- Institut für Experimentalphysik, Universität Innsbruck, Technikerstrasse 25, 6020 Innsbruck, Austria
- Institut für Quantenoptik und Quanteninformation, Österreichische Akademie der Wissenschaften, 6020 Innsbruck, Austria
| | - M Mark
- Institut für Experimentalphysik, Universität Innsbruck, Technikerstrasse 25, 6020 Innsbruck, Austria
| | - K Aikawa
- Institut für Experimentalphysik, Universität Innsbruck, Technikerstrasse 25, 6020 Innsbruck, Austria
| | - S Baier
- Institut für Experimentalphysik, Universität Innsbruck, Technikerstrasse 25, 6020 Innsbruck, Austria
| | - R Grimm
- Institut für Experimentalphysik, Universität Innsbruck, Technikerstrasse 25, 6020 Innsbruck, Austria
- Institut für Quantenoptik und Quanteninformation, Österreichische Akademie der Wissenschaften, 6020 Innsbruck, Austria
| | - A Petrov
- Department of Physics, Temple University, Philadelphia, Pennsylvania 19122, USA
| | - S Kotochigova
- Department of Physics, Temple University, Philadelphia, Pennsylvania 19122, USA
| | - G Quéméner
- Laboratoire Aimé Cotton, CNRS, Université Paris-Sud, ENS Cachan, 91405 Orsay, France
| | - M Lepers
- Laboratoire Aimé Cotton, CNRS, Université Paris-Sud, ENS Cachan, 91405 Orsay, France
| | - O Dulieu
- Laboratoire Aimé Cotton, CNRS, Université Paris-Sud, ENS Cachan, 91405 Orsay, France
| | - F Ferlaino
- Institut für Experimentalphysik, Universität Innsbruck, Technikerstrasse 25, 6020 Innsbruck, Austria
- Institut für Quantenoptik und Quanteninformation, Österreichische Akademie der Wissenschaften, 6020 Innsbruck, Austria
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27
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Massignan P, Zaccanti M, Bruun GM. Polarons, dressed molecules and itinerant ferromagnetism in ultracold Fermi gases. REPORTS ON PROGRESS IN PHYSICS. PHYSICAL SOCIETY (GREAT BRITAIN) 2014; 77:034401. [PMID: 24553400 DOI: 10.1088/0034-4885/77/3/034401] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
In this review, we discuss the properties of a few impurity atoms immersed in a gas of ultracold fermions--the so-called Fermi polaron problem. On one hand, this many-body system is appealing because it can be described almost exactly with simple diagrammatic and/or variational theoretical approaches. On the other, it provides a quantitatively reliable insight into the phase diagram of strongly interacting population-imbalanced quantum mixtures. In particular, we show that the polaron problem can be applied to the study of itinerant ferromagnetism, a long-standing problem in quantum mechanics.
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Affiliation(s)
- Pietro Massignan
- ICFO-Institut de Ciències Fotòniques, Mediterranean Technology Park, E-08860 Castelldefels, Barcelona, Spain
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28
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Jag M, Zaccanti M, Cetina M, Lous RS, Schreck F, Grimm R, Petrov DS, Levinsen J. Observation of a strong atom-dimer attraction in a mass-imbalanced Fermi-Fermi mixture. PHYSICAL REVIEW LETTERS 2014; 112:075302. [PMID: 24579609 DOI: 10.1103/physrevlett.112.075302] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/20/2013] [Indexed: 06/03/2023]
Abstract
We investigate a mixture of ultracold fermionic K40 atoms and weakly bound Li6K40 dimers on the repulsive side of a heteronuclear atomic Feshbach resonance. By radio-frequency spectroscopy we demonstrate that the normally repulsive atom-dimer interaction is turned into a strong attraction. The phenomenon can be understood as a three-body effect in which two heavy K40 fermions exchange the light Li6 atom, leading to attraction in odd partial-wave channels (mainly p wave). Our observations show that mass imbalance in a fermionic system can profoundly change the character of interactions as compared to the well-established mass-balanced case.
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Affiliation(s)
- Michael Jag
- Institut für Quantenoptik und Quanteninformation (IQOQI), Österreichische Akademie der Wissenschaften, 6020 Innsbruck, Austria and Institut für Experimentalphysik, Universität Innsbruck, 6020 Innsbruck, Austria
| | - Matteo Zaccanti
- Institut für Quantenoptik und Quanteninformation (IQOQI), Österreichische Akademie der Wissenschaften, 6020 Innsbruck, Austria and CNR Istituto Nazionale Ottica, 50019 Sesto Fiorentino, Italy
| | - Marko Cetina
- Institut für Quantenoptik und Quanteninformation (IQOQI), Österreichische Akademie der Wissenschaften, 6020 Innsbruck, Austria
| | - Rianne S Lous
- Institut für Quantenoptik und Quanteninformation (IQOQI), Österreichische Akademie der Wissenschaften, 6020 Innsbruck, Austria and Institut für Experimentalphysik, Universität Innsbruck, 6020 Innsbruck, Austria
| | - Florian Schreck
- Institut für Quantenoptik und Quanteninformation (IQOQI), Österreichische Akademie der Wissenschaften, 6020 Innsbruck, Austria
| | - Rudolf Grimm
- Institut für Quantenoptik und Quanteninformation (IQOQI), Österreichische Akademie der Wissenschaften, 6020 Innsbruck, Austria and Institut für Experimentalphysik, Universität Innsbruck, 6020 Innsbruck, Austria
| | - Dmitry S Petrov
- Université Paris-Sud, CNRS, LPTMS, UMR8626, Orsay F-91405, France
| | - Jesper Levinsen
- TCM group, Cavendish Laboratory, JJ Thomson Avenue, Cambridge CB3 0HE, United Kingdom and Aarhus Institute of Advanced Studies, Aarhus University, DK-8000 Aarhus C, Denmark
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29
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Lan Z, Bruun GM, Lobo C. Quasiparticle lifetime in ultracold fermionic mixtures with density and mass imbalance. PHYSICAL REVIEW LETTERS 2013; 111:145301. [PMID: 24138248 DOI: 10.1103/physrevlett.111.145301] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2013] [Revised: 05/15/2013] [Indexed: 06/02/2023]
Abstract
We show that atomic Fermi mixtures with density and mass imbalance exhibit a rich diversity of scaling laws for the quasiparticle decay rate beyond the quadratic energy and temperature dependence of conventional Fermi liquids. For certain densities and mass ratios, the decay rate is linear, whereas in other cases, it exhibits a plateau. Remarkably, this plateau extends from the deeply degenerate to the high temperature classical regime of the light species. Many of these scaling laws are analogous to what is found in very different systems, including dirty metals, liquid metals, and high temperature plasmas. The Fermi mixtures can in this sense span a whole range of seemingly diverse and separate physical systems. Our results are derived in the weakly interacting limit, making them quantitatively reliable. The different regimes can be detected with radio-frequency spectroscopy.
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Affiliation(s)
- Zhihao Lan
- Mathematical Sciences, University of Southampton, Highfield, Southampton, SO17 1BJ, United Kingdom
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30
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Kim DH, Lehikoinen JSJ, Törmä P. Topological transitions of gapless paired states in mixed-geometry lattices. PHYSICAL REVIEW LETTERS 2013; 110:055301. [PMID: 23414027 DOI: 10.1103/physrevlett.110.055301] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2012] [Indexed: 06/01/2023]
Abstract
We propose a mixed-geometry system of fermionic species selectively confined in lattices of different geometry. We investigate how such asymmetry can lead to exotic multiband fermion pairing in an example system of honeycomb and triangular lattices. A rich phase diagram of interband pairing with gapped and gapless excitations is found at zero temperature. We find that the two-band contribution of the honeycomb lattices to the paired state helps to stabilize the gapless phase with one or two Fermi surfaces. We also show that the Fermi surface topology further divides the gapless phase into subclasses between which the system undergoes density-driven Lifshitz transitions.
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Affiliation(s)
- Dong-Hee Kim
- COMP Centre of Excellence, Department of Applied Physics, Aalto University, FI-00076 Aalto, Finland
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31
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Blume D. Universal four-body states in heavy-light mixtures with a positive scattering length. PHYSICAL REVIEW LETTERS 2012; 109:230404. [PMID: 23368171 DOI: 10.1103/physrevlett.109.230404] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/14/2012] [Indexed: 06/01/2023]
Abstract
The number of four-body states known to behave universally is small. This work adds a new class of four-body states to this relatively short list. We predict the existence of a universal four-body bound state for heavy-light mixtures consisting of three identical heavy fermions and a fourth distinguishable lighter particle with a mass ratio κ>/~9.5 and short-range interspecies interaction characterized by a positive s-wave scattering length. The structural properties of these universal states are discussed, and finite-range effects are analyzed. The bound states can be experimentally realized and probed by utilizing ultracold atom mixtures.
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Affiliation(s)
- D Blume
- Department of Physics and Astronomy, Washington State University, Pullman, Washington 99164-2814, USA
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32
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Li J, An J, Ting CS. Interaction-induced localization of fermionic mobile impurities in a Larkin-Ovchinnikov superfluid. PHYSICAL REVIEW LETTERS 2012; 109:196402. [PMID: 23215409 DOI: 10.1103/physrevlett.109.196402] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2012] [Indexed: 06/01/2023]
Abstract
We theoretically investigate the interplay between the fermionic mobile impurity atoms and a Larkin-Ovchinnikov (LO) superfluid in a two dimensional optical lattice. We find that the impurity atoms get localized and can form pairs when the interaction between the impurity atoms and the LO superfluid is strong enough. These features are due to the phenomena of self-localization whose underlying mechanism is revealed by an effective model. The impurity atoms with finite concentrations can drive the transition from a two-dimensional, checkerboardlike LO state to a quasi-one-dimensional, stripelike one. Experimental preparations to observe these features are also discussed.
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Affiliation(s)
- Jian Li
- Texas Center for Superconductivity and Department of Physics, University of Houston, Houston, Texas 77204, USA
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33
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Ulmanis J, Deiglmayr J, Repp M, Wester R, Weidemüller M. Ultracold Molecules Formed by Photoassociation: Heteronuclear Dimers, Inelastic Collisions, and Interactions with Ultrashort Laser Pulses. Chem Rev 2012; 112:4890-927. [PMID: 22931226 DOI: 10.1021/cr300215h] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Juris Ulmanis
- Physikalisches Institut, Ruprecht-Karls-Universität Heidelberg, Philosophenweg
12, 69120 Heidelberg, Germany
| | - Johannes Deiglmayr
- Laboratorium für Physikalische
Chemie, ETH Zürich, Wolfgang-Pauli-Strasse
10, 8093 Zürich, Switzerland
| | - Marc Repp
- Physikalisches Institut, Ruprecht-Karls-Universität Heidelberg, Philosophenweg
12, 69120 Heidelberg, Germany
| | - Roland Wester
- Institut für Ionenphysik
und Angewandte Physik, Universität Innsbruck, Technikerstrasse 25/3, 6020 Innsbruck, Austria
| | - Matthias Weidemüller
- Physikalisches Institut, Ruprecht-Karls-Universität Heidelberg, Philosophenweg
12, 69120 Heidelberg, Germany
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34
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Yang Y, Liu X, Zhao Y, Xiao L, Jia S. Rovibrational Dynamics of RbCs on its Lowest 1,3Σ+ Potential Curves Calculated by Coupled Cluster Method with All-Electron Basis Set. J Phys Chem A 2012; 116:11101-6. [DOI: 10.1021/jp303975x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Affiliation(s)
- Yonggang Yang
- State Key Laboratory of Quantum Optics
and Quantum
Optics Devices, Laser Spectroscopy Laboratory, Shanxi University, Taiyuan 030006, China
| | - Xiaomeng Liu
- State Key Laboratory of Quantum Optics
and Quantum
Optics Devices, Laser Spectroscopy Laboratory, Shanxi University, Taiyuan 030006, China
| | - Yanting Zhao
- State Key Laboratory of Quantum Optics
and Quantum
Optics Devices, Laser Spectroscopy Laboratory, Shanxi University, Taiyuan 030006, China
| | - Liantuan Xiao
- State Key Laboratory of Quantum Optics
and Quantum
Optics Devices, Laser Spectroscopy Laboratory, Shanxi University, Taiyuan 030006, China
| | - Suotang Jia
- State Key Laboratory of Quantum Optics
and Quantum
Optics Devices, Laser Spectroscopy Laboratory, Shanxi University, Taiyuan 030006, China
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35
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Levinsen J, Massignan P, Chevy F, Lobo C. p-Wave polaron. PHYSICAL REVIEW LETTERS 2012; 109:075302. [PMID: 23006381 DOI: 10.1103/physrevlett.109.075302] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2012] [Indexed: 06/01/2023]
Abstract
We consider a single impurity immersed in a Fermi sea close to an interspecies p-wave Feshbach resonance. We calculate its dispersion and spectral response to a radio frequency pulse. In a magnetic field, dipolar interactions split the resonance and two novel features with respect to the s-wave case appear: a third polaron branch in the excitation spectrum, in addition to the usual attractive and repulsive ones; and an anisotropic dispersion of the impurity characterized by different effective masses perpendicular and parallel to the magnetic field. The anisotropy can be tuned as a function of the field strength and the two effective masses may have opposite signs, or become smaller than the bare mass.
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Affiliation(s)
- Jesper Levinsen
- T.C.M. Group, Cavendish Laboratory, Cambridge, United Kingdom.
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36
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Hazlett EL, Zhang Y, Stites RW, O'Hara KM. Realization of a resonant Fermi gas with a large effective range. PHYSICAL REVIEW LETTERS 2012; 108:045304. [PMID: 22400855 DOI: 10.1103/physrevlett.108.045304] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/24/2011] [Indexed: 05/31/2023]
Abstract
We have measured the interaction energy and three-body recombination rate for a two-component Fermi gas near a narrow Feshbach resonance and found both to be strongly energy dependent. Even for de Broglie wavelengths greatly exceeding the van der Waals length scale, the behavior of the interaction energy as a function of temperature cannot be described by atoms interacting via a contact potential. Rather, energy-dependent corrections beyond the scattering length approximation are required, indicating a resonance with an anomalously large effective range. For fields where the molecular state is above threshold, the rate of three-body recombination is enhanced by a sharp, two-body resonance arising from the closed-channel molecular state which can be magnetically tuned through the continuum. This narrow resonance can be used to study strongly correlated Fermi gases that simultaneously have a sizable effective range and a large scattering length.
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Affiliation(s)
- E L Hazlett
- Department of Physics, Pennsylvania State University, University Park, Pennsylvania 16802-6300, USA
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37
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Trenkwalder A, Kohstall C, Zaccanti M, Naik D, Sidorov AI, Schreck F, Grimm R. Hydrodynamic expansion of a strongly interacting fermi-fermi mixture. PHYSICAL REVIEW LETTERS 2011; 106:115304. [PMID: 21469874 DOI: 10.1103/physrevlett.106.115304] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2010] [Revised: 01/13/2011] [Indexed: 05/30/2023]
Abstract
We report on the expansion of an ultracold Fermi-Fermi mixture of (6)Li and (40)K under conditions of strong interactions controlled via an interspecies Feshbach resonance. We study the expansion of the mixture after release from the trap and, in a narrow magnetic-field range, we observe two phenomena related to hydrodynamic behavior. The common inversion of the aspect ratio is found to be accompanied by a collective effect where both species stick together and expand jointly despite of their widely different masses. Our work constitutes a major experimental step for a controlled investigation of the many-body physics of this novel strongly interacting quantum system.
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Affiliation(s)
- A Trenkwalder
- Institut für Quantenoptik und Quanteninformation, Österreichische Akademie der Wissenschaften, 6020 Innsbruck, Austria
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38
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Costa L, Brachmann J, Voigt AC, Hahn C, Taglieber M, Hänsch TW, Dieckmann K. s-Wave interaction in a two-species Fermi-Fermi mixture at a narrow Feshbach resonance. PHYSICAL REVIEW LETTERS 2010; 105:123201. [PMID: 20867635 DOI: 10.1103/physrevlett.105.123201] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2010] [Indexed: 05/29/2023]
Abstract
We investigate s-wave interactions in a two-species Fermi-Fermi mixture of 6Li and 40K. We develop for this case the method of cross-dimensional relaxation and find from a kinetic model, Monte Carlo simulations, and measurements that the individual relaxation rates differ due to the mass difference. The method is applied to measure the elastic cross section at the Feshbach resonance that we previously used for the production of heteronuclear molecules. Location (B0=155.09(5) G) and width are determined for this resonance. This reveals that molecules are being produced on the atomic side of the resonance within a range related to the Fermi energies, therefore establishing the first observation of a many body effect in the crossover regime of a narrow Feshbach resonance.
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Affiliation(s)
- L Costa
- Department für Physik der Ludwig-Maximilians-Universität, Schellingstraße 4, 80799 Munich, Germany
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39
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Orso G, Burovski E, Jolicoeur T. Luttinger liquid of trimers in Fermi gases with unequal masses. PHYSICAL REVIEW LETTERS 2010; 104:065301. [PMID: 20366827 DOI: 10.1103/physrevlett.104.065301] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2009] [Revised: 12/09/2009] [Indexed: 05/29/2023]
Abstract
We investigate one dimensional attractive Fermi gases in spin-dependent optical lattices. We show that three-body bound states--"trimers"--exist as soon as the two tunneling rates are different. We calculate the binding energy and the effective mass of a single trimer. We then show numerically that for finite and commensurate densities n(up) = n(down)/2 an energy gap appears, implying that the gas is a one-component Luttinger liquid of trimers with suppressed superfluid correlations. The boundaries of this novel phase are given. We discuss experimental situations to test our predictions.
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Affiliation(s)
- Giuliano Orso
- Laboratoire de Physique Théorique et Modèles statistiques, Université Paris-Sud, 91405 Orsay, France
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40
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Tiecke TG, Goosen MR, Ludewig A, Gensemer SD, Kraft S, Kokkelmans SJJMF, Walraven JTM. Broad Feshbach resonance in the 6Li-40K mixture. PHYSICAL REVIEW LETTERS 2010; 104:053202. [PMID: 20366760 DOI: 10.1103/physrevlett.104.053202] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2009] [Indexed: 05/29/2023]
Abstract
We study the widths of interspecies Feshbach resonances in a mixture of the fermionic quantum gases 6Li and 40K. We develop a model to calculate the width and position of all available Feshbach resonances for a system. Using the model, we select the optimal resonance to study the {6}Li/{40}K mixture. Experimentally, we obtain the asymmetric Fano line shape of the interspecies elastic cross section by measuring the distillation rate of 6Li atoms from a potassium-rich 6Li/{40}K mixture as a function of magnetic field. This provides us with the first experimental determination of the width of a resonance in this mixture, DeltaB=1.5(5) G. Our results offer good perspectives for the observation of universal crossover physics using this mass-imbalanced fermionic mixture.
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Affiliation(s)
- T G Tiecke
- van der Waals-Zeeman Institute of the University of Amsterdam, Valckenierstraat 65, 1018 XE, The Netherlands
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41
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Martikainen JP, Kinnunen JJ, Törmä P, Pethick CJ. Induced interactions and the superfluid transition temperature in a three-component Fermi gas. PHYSICAL REVIEW LETTERS 2009; 103:260403. [PMID: 20366298 DOI: 10.1103/physrevlett.103.260403] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/26/2009] [Revised: 12/04/2009] [Indexed: 05/29/2023]
Abstract
We study many-body contributions to the effective interaction between fermions in a three-component Fermi mixture. We find that effective interactions induced by the third component can lead to a phase diagram different from that predicted if interactions with the third component are neglected. As a result, in a confining potential a superfluid shell structure can arise even for equal populations of the components. We also find a critical temperature for the BCS transition in a 6Li mixture which can deviate strongly from the one in a weakly interacting two-component system.
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42
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Kantian A, Dalmonte M, Diehl S, Hofstetter W, Zoller P, Daley AJ. Atomic color superfluid via three-body loss. PHYSICAL REVIEW LETTERS 2009; 103:240401. [PMID: 20366187 DOI: 10.1103/physrevlett.103.240401] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2009] [Revised: 11/13/2009] [Indexed: 05/29/2023]
Abstract
Large three-body loss rates in a three-component Fermi gas confined in an optical lattice can dynamically prevent atoms from tunneling so as to occupy a lattice site with three atoms. This effective constraint not only suppresses the occurrence of actual loss events, but stabilizes BCS-pairing phases by suppressing the formation of trions. We study the effect of the constraint on the many-body physics using bosonization and density matrix renormalization group techniques, and also investigate the full dissipative dynamics including loss for the example of 6Li.
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Affiliation(s)
- A Kantian
- Institute for Theoretical Physics, University of Innsbruck, A-6020 Innsbruck, Austria
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43
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Spiegelhalder FM, Trenkwalder A, Naik D, Hendl G, Schreck F, Grimm R. Collisional stability of 40K immersed in a strongly interacting Fermi gas of 6Li. PHYSICAL REVIEW LETTERS 2009; 103:223203. [PMID: 20366094 DOI: 10.1103/physrevlett.103.223203] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2009] [Revised: 09/29/2009] [Indexed: 05/29/2023]
Abstract
We investigate the collisional stability of a sample of 40K atoms immersed in a tunable spin mixture of 6Li atoms. In this three-component Fermi-Fermi mixture, we find very low loss rates in a wide range of interactions as long as molecule formation of 6Li is avoided. The stable fermionic mixture with two resonantly interacting spin states of one species together with another species is a promising system for a broad variety of phenomena in few- and many-body quantum physics.
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Affiliation(s)
- F M Spiegelhalder
- Institut für Quantenoptik und Quanteninformation, Osterreichische Akademie der Wissenschaften, 6020 Innsbruck, Austria
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44
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Gubbels KB, Baarsma JE, Stoof HTC. Lifshitz point in the phase diagram of resonantly interacting 6Li-40K mixtures. PHYSICAL REVIEW LETTERS 2009; 103:195301. [PMID: 20365934 DOI: 10.1103/physrevlett.103.195301] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2009] [Revised: 10/16/2009] [Indexed: 05/29/2023]
Abstract
We consider a strongly interacting 6Li-40K mixture, which is imbalanced both in the masses and the densities of the two fermionic species. At present, it is the experimentalist's favorite for reaching the superfluid regime. We construct an effective thermodynamic potential that leads to excellent agreement with Monte Carlo results for the normal state. We use it to determine the universal phase diagram of the mixture in the unitarity limit, where we find, in contrast to the mass-balanced case, the presence of a Lifshitz point. This point is characterized by the effective mass of the Cooper pairs becoming negative, which signals an instability towards a supersolid phase.
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Affiliation(s)
- K B Gubbels
- Institute for Theoretical Physics, Utrecht University, Leuvenlaan 4, 3584 CE Utrecht, The Netherlands.
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45
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Levinsen J, Tiecke TG, Walraven JTM, Petrov DS. Atom-dimer scattering and long-lived trimers in fermionic mixtures. PHYSICAL REVIEW LETTERS 2009; 103:153202. [PMID: 19905636 DOI: 10.1103/physrevlett.103.153202] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2009] [Indexed: 05/28/2023]
Abstract
We consider a heteronuclear fermionic mixture on the molecular side of an interspecies Feshbach resonance and discuss atom-dimer scattering properties in uniform space and in the presence of an external confining potential, restricting the system to a quasi-two-dimensional geometry. We find that there is a peculiar atom-dimer p-wave resonance which can be tuned by changing the frequency of the confinement. Our results have implications for the ongoing experiments on lithium-potassium mixtures, where this mechanism allows for switching the p-wave interaction between a K atom and Li-K dimer from attractive to repulsive, and forming a weakly bound trimer with unit angular momentum. We show that such trimers are long lived and the atom-dimer resonance does not enhance inelastic relaxation in the mixture, making it an outstanding candidate for studies of p-wave resonance effects in a many-body system.
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Affiliation(s)
- J Levinsen
- Laboratoire Physique Théorique et Modèles Statistique, Université Paris Sud, CNRS, 91405 Orsay, France
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46
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47
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Zhang P, Naidon P, Ueda M. Independent control of scattering lengths in multicomponent quantum gases. PHYSICAL REVIEW LETTERS 2009; 103:133202. [PMID: 19905512 DOI: 10.1103/physrevlett.103.133202] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/06/2009] [Indexed: 05/28/2023]
Abstract
We develop a method of simultaneous and independent control of different scattering lengths in ultracold atomic gases, such as ;{40}K or a ;{40}K-;{6}Li mixture. Our method can be used to engineer multicomponent quantum phases and Efimov trimer states.
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Affiliation(s)
- Peng Zhang
- ERATO, JST, Macroscopic Quantum Control Project, Hongo, Bunkyo-Ku, Tokyo 113-8656, Japan
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48
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Gezerlis A, Gandolfi S, Schmidt KE, Carlson J. Heavy-light fermion mixtures at unitarity. PHYSICAL REVIEW LETTERS 2009; 103:060403. [PMID: 19792545 DOI: 10.1103/physrevlett.103.060403] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2009] [Revised: 06/29/2009] [Indexed: 05/28/2023]
Abstract
We investigate fermion pairing in the unitary regime for a mass ratio corresponding to a ;{6}Li-;{40}K mixture using quantum Monte Carlo methods. The ground-state energy and the average light- and heavy-particle excitation spectrum for the unpolarized superfluid state are nearly independent of the mass ratio. In the majority light system, the polarized superfluid is close to the energy of a phase separated mixture of nearly fully polarized normal and unpolarized superfluid. For a majority of heavy particles, we find an energy minimum for a normal state with a ratio of approximately 3ratio1 heavy to light particles. A slight increase in attraction to k_{F}a approximately 2.5 yields a ground state energy of nearly zero for this ratio. A cold unpolarized system in a harmonic trap at unitarity should phase separate into three regions, with a shell of unpolarized superfluid in the middle.
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Affiliation(s)
- Alexandros Gezerlis
- Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
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49
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50
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Voigt AC, Taglieber M, Costa L, Aoki T, Wieser W, Hänsch TW, Dieckmann K. Ultracold heteronuclear fermi-fermi molecules. PHYSICAL REVIEW LETTERS 2009; 102:020405. [PMID: 19257253 DOI: 10.1103/physrevlett.102.020405] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2008] [Indexed: 05/27/2023]
Abstract
We report on the first creation of ultracold bosonic heteronuclear molecules of two fermionic species, 6Li and 40K, by a magnetic field sweep across an interspecies s-wave Feshbach resonance. This allows us to associate up to 4x10(4) molecules with high efficiencies of up to 50%. Using direct imaging of the molecules, we measure increased lifetimes of the molecules close to resonance of more than 100 ms in the molecule-atom mixture stored in a harmonic trap.
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Affiliation(s)
- A-C Voigt
- Department für Physik der Ludwig-Maximilians-Universität, Schellingstrasse 4, 80799 Munich, Germany.
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