1
|
Bachmann D, Klug A, Isoard M, Shatokhin V, Sorelli G, Buchleitner A, Forbes A. Universal Crosstalk of Twisted Light in Random Media. Phys Rev Lett 2024; 132:063801. [PMID: 38394585 DOI: 10.1103/physrevlett.132.063801] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2022] [Accepted: 12/12/2023] [Indexed: 02/25/2024]
Abstract
Structured light offers wider bandwidths and higher security for communication. However, propagation through complex random media, such as the Earth's atmosphere, typically induces intermodal crosstalk. We show numerically and experimentally that coupling of photonic orbital angular momentum modes is governed by a universal function of a single parameter: the ratio between the random medium's and the beam's transverse correlation lengths, even in the regime of pronounced intensity fluctuations.
Collapse
Affiliation(s)
- David Bachmann
- Physikalisches Institut, Albert-Ludwigs-Universität Freiburg, Hermann-Herder-Straße 3, D-79104 Freiburg, Germany
| | - Asher Klug
- School of Physics, University of the Witwatersrand, Private Bag 3, Johannesburg 2050, South Africa
| | - Mathieu Isoard
- Physikalisches Institut, Albert-Ludwigs-Universität Freiburg, Hermann-Herder-Straße 3, D-79104 Freiburg, Germany
| | - Vyacheslav Shatokhin
- Physikalisches Institut, Albert-Ludwigs-Universität Freiburg, Hermann-Herder-Straße 3, D-79104 Freiburg, Germany
- EUCOR Centre for Quantum Science and Quantum Computing, Albert-Ludwigs-Universität Freiburg, Hermann-Herder-Straße 3, D-79104 Freiburg, Germany
| | - Giacomo Sorelli
- Laboratoire Kastler Brossel, Sorbonne Université, ENS-Université PSL, Collège de France, CNRS; 4 place Jussieu, F-75252 Paris, France
| | - Andreas Buchleitner
- Physikalisches Institut, Albert-Ludwigs-Universität Freiburg, Hermann-Herder-Straße 3, D-79104 Freiburg, Germany
- EUCOR Centre for Quantum Science and Quantum Computing, Albert-Ludwigs-Universität Freiburg, Hermann-Herder-Straße 3, D-79104 Freiburg, Germany
| | - Andrew Forbes
- School of Physics, University of the Witwatersrand, Private Bag 3, Johannesburg 2050, South Africa
| |
Collapse
|
2
|
Englbrecht M, Kraft T, Dittel C, Buchleitner A, Giedke G, Kraus B. Indistinguishability of Identical Bosons from a Quantum Information Theory Perspective. Phys Rev Lett 2024; 132:050201. [PMID: 38364122 DOI: 10.1103/physrevlett.132.050201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/22/2023] [Revised: 12/14/2023] [Accepted: 01/03/2024] [Indexed: 02/18/2024]
Abstract
Using tools from quantum information theory, we present a general theory of indistinguishability of identical bosons in experiments consisting of passive linear optics followed by particle number detection. Our results do neither rely on additional assumptions on the input state of the interferometer, such as, for instance, a fixed mode occupation, nor on any assumption on the degrees of freedom that potentially make the particles distinguishable. We identify the expectation value of the projector onto the N-particle symmetric subspace as an operationally meaningful measure of indistinguishability, and derive tight lower bounds on it that can be efficiently measured in experiments. Moreover, we present a consistent definition of perfect distinguishability and characterize the corresponding set of states. In particular, we show that these states are diagonal in the computational basis up to a permutationally invariant unitary. Moreover, we find that convex combinations of states that describe partially distinguishable and perfectly indistinguishable particles can lead to perfect distinguishability, which itself is not preserved under convex combinations.
Collapse
Affiliation(s)
- Matthias Englbrecht
- Department of Physics, QAA, Technical University of Munich, James-Franck-Straße 1, D-85748 Garching, Germany
- Institute for Theoretical Physics, University of Innsbruck, Technikerstraße 21A, 6020 Innsbruck, Austria
| | - Tristan Kraft
- Department of Physics, QAA, Technical University of Munich, James-Franck-Straße 1, D-85748 Garching, Germany
- Institute for Theoretical Physics, University of Innsbruck, Technikerstraße 21A, 6020 Innsbruck, Austria
| | - Christoph Dittel
- Physikalisches Institut, Albert-Ludwigs-Universität Freiburg, Hermann-Herder-Straße 3, 79104 Freiburg, Germany
- EUCOR Centre for Quantum Science and Quantum Computing, Albert-Ludwigs-Universität Freiburg, Hermann-Herder-Straße 3, D-79104 Freiburg, Germany
- Freiburg Institute for Advanced Studies, Albert-Ludwigs-Universität Freiburg, Albertstraße 19, D-79104 Freiburg, Germany
| | - Andreas Buchleitner
- Physikalisches Institut, Albert-Ludwigs-Universität Freiburg, Hermann-Herder-Straße 3, 79104 Freiburg, Germany
- EUCOR Centre for Quantum Science and Quantum Computing, Albert-Ludwigs-Universität Freiburg, Hermann-Herder-Straße 3, D-79104 Freiburg, Germany
| | - Geza Giedke
- Donostia International Physics Center (DIPC), Paseo Manuel de Lardizabal 4, E-20018 San Sebastián, Spain
- IKERBASQUE, Basque Foundation for Science, Plaza Euskadi 5, E-48009 Bilbao, Spain
| | - Barbara Kraus
- Department of Physics, QAA, Technical University of Munich, James-Franck-Straße 1, D-85748 Garching, Germany
- Institute for Theoretical Physics, University of Innsbruck, Technikerstraße 21A, 6020 Innsbruck, Austria
| |
Collapse
|
3
|
Lindel F, Carnio EG, Buhmann SY, Buchleitner A. Quantized Fields for Optimal Control in the Strong Coupling Regime. Phys Rev Lett 2023; 130:133601. [PMID: 37067298 DOI: 10.1103/physrevlett.130.133601] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Revised: 01/16/2023] [Accepted: 02/16/2023] [Indexed: 06/19/2023]
Abstract
We tailor the quantum statistics of a bosonic field to deterministically drive a quantum system into a target state. Experimentally accessible states of the field achieve good control of multilevel or multiqubit systems, notably also at coupling strengths beyond the rotating-wave approximation. This extends optimal control theory to the realm of fully quantized, strongly coupled control and target degrees of freedom.
Collapse
Affiliation(s)
- Frieder Lindel
- Physikalisches Institut, Albert-Ludwigs-Universität Freiburg, Hermann-Herder-Straße 3, 79104, Freiburg, Germany
| | - Edoardo G Carnio
- Physikalisches Institut, Albert-Ludwigs-Universität Freiburg, Hermann-Herder-Straße 3, 79104, Freiburg, Germany
- EUCOR Centre for Quantum Science and Quantum Computing, Albert-Ludwigs-Universität Freiburg, Hermann-Herder-Straße 3, 79104, Freiburg, Germany
| | - Stefan Yoshi Buhmann
- Institut für Physik, Universität Kassel, Heinrich-Plett-Straße 40, 34132 Kassel, Germany
| | - Andreas Buchleitner
- Physikalisches Institut, Albert-Ludwigs-Universität Freiburg, Hermann-Herder-Straße 3, 79104, Freiburg, Germany
- EUCOR Centre for Quantum Science and Quantum Computing, Albert-Ludwigs-Universität Freiburg, Hermann-Herder-Straße 3, 79104, Freiburg, Germany
| |
Collapse
|
4
|
Brunner E, Pausch L, Carnio EG, Dufour G, Rodríguez A, Buchleitner A. Many-Body Interference at the Onset of Chaos. Phys Rev Lett 2023; 130:080401. [PMID: 36898099 DOI: 10.1103/physrevlett.130.080401] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2022] [Revised: 01/16/2023] [Accepted: 01/27/2023] [Indexed: 06/18/2023]
Abstract
We unveil the signature of many-body interference across dynamical regimes of the Bose-Hubbard model. Increasing the particles' indistinguishability enhances the temporal fluctuations of few-body observables, with a dramatic amplification at the onset of quantum chaos. By resolving the exchange symmetries of partially distinguishable particles, we explain this amplification as the fingerprint of the initial state's coherences in the eigenbasis.
Collapse
Affiliation(s)
- Eric Brunner
- Physikalisches Institut, Albert-Ludwigs-Universität Freiburg, Hermann-Herder-Straße 3, 79104, Freiburg, Germany
- EUCOR Centre for Quantum Science and Quantum Computing, Albert-Ludwigs-Universität Freiburg, Hermann-Herder-Straße 3, 79104, Freiburg, Germany
| | - Lukas Pausch
- Physikalisches Institut, Albert-Ludwigs-Universität Freiburg, Hermann-Herder-Straße 3, 79104, Freiburg, Germany
- EUCOR Centre for Quantum Science and Quantum Computing, Albert-Ludwigs-Universität Freiburg, Hermann-Herder-Straße 3, 79104, Freiburg, Germany
| | - Edoardo G Carnio
- Physikalisches Institut, Albert-Ludwigs-Universität Freiburg, Hermann-Herder-Straße 3, 79104, Freiburg, Germany
- EUCOR Centre for Quantum Science and Quantum Computing, Albert-Ludwigs-Universität Freiburg, Hermann-Herder-Straße 3, 79104, Freiburg, Germany
| | - Gabriel Dufour
- Physikalisches Institut, Albert-Ludwigs-Universität Freiburg, Hermann-Herder-Straße 3, 79104, Freiburg, Germany
- EUCOR Centre for Quantum Science and Quantum Computing, Albert-Ludwigs-Universität Freiburg, Hermann-Herder-Straße 3, 79104, Freiburg, Germany
| | - Alberto Rodríguez
- Departamento de Física Fundamental, Universidad de Salamanca, E-37008 Salamanca, Spain
- Instituto Universitario de Física Fundamental y Matemáticas (IUFFyM), Universidad de Salamanca, E-37008 Salamanca, Spain
| | - Andreas Buchleitner
- Physikalisches Institut, Albert-Ludwigs-Universität Freiburg, Hermann-Herder-Straße 3, 79104, Freiburg, Germany
- EUCOR Centre for Quantum Science and Quantum Computing, Albert-Ludwigs-Universität Freiburg, Hermann-Herder-Straße 3, 79104, Freiburg, Germany
| |
Collapse
|
5
|
Bachmann D, Isoard M, Shatokhin V, Sorelli G, Treps N, Buchleitner A. Highly Transmitting Modes of Light in Dynamic Atmospheric Turbulence. Phys Rev Lett 2023; 130:073801. [PMID: 36867810 DOI: 10.1103/physrevlett.130.073801] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Accepted: 12/12/2022] [Indexed: 06/18/2023]
Abstract
We show that instantaneous spatial singular modes of light in a dynamically evolving, turbulent atmosphere offer significantly improved high-fidelity signal transmission as compared to standard encoding bases corrected by adaptive optics. Their enhanced stability in stronger turbulence is associated with a subdiffusive algebraic decay of the transmitted power with evolution time.
Collapse
Affiliation(s)
- David Bachmann
- Physikalisches Institut, Albert-Ludwigs-Universität Freiburg, Hermann-Herder-Straße 3, D-79104 Freiburg, Germany
| | - Mathieu Isoard
- Physikalisches Institut, Albert-Ludwigs-Universität Freiburg, Hermann-Herder-Straße 3, D-79104 Freiburg, Germany
| | - Vyacheslav Shatokhin
- Physikalisches Institut, Albert-Ludwigs-Universität Freiburg, Hermann-Herder-Straße 3, D-79104 Freiburg, Germany
- EUCOR Centre for Quantum Science and Quantum Computing, Albert-Ludwigs-Universität Freiburg, Hermann-Herder-Straße 3, D-79104 Freiburg, Germany
| | - Giacomo Sorelli
- Laboratoire Kastler Brossel, Sorbonne Université, ENS-Université PSL, Collège de France, CNRS, 4 place Jussieu, F-75252 Paris, France
| | - Nicolas Treps
- Laboratoire Kastler Brossel, Sorbonne Université, ENS-Université PSL, Collège de France, CNRS, 4 place Jussieu, F-75252 Paris, France
| | - Andreas Buchleitner
- Physikalisches Institut, Albert-Ludwigs-Universität Freiburg, Hermann-Herder-Straße 3, D-79104 Freiburg, Germany
- EUCOR Centre for Quantum Science and Quantum Computing, Albert-Ludwigs-Universität Freiburg, Hermann-Herder-Straße 3, D-79104 Freiburg, Germany
| |
Collapse
|
6
|
Ames B, Buchleitner A, Carnio EG, Shatokhin VN. Publisher's Note: "Pulse area dependence of multiple quantum coherence signals in dilute thermal gases" [J. Chem. Phys. 155, 044306 (2021)]. J Chem Phys 2021; 155:079902. [PMID: 34418938 DOI: 10.1063/5.0065741] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Benedikt Ames
- Physikalisches Institut, Albert-Ludwigs-Universität Freiburg, Hermann-Herder-Str. 3, D-79104 Freiburg, Germany
| | - Andreas Buchleitner
- Physikalisches Institut, Albert-Ludwigs-Universität Freiburg, Hermann-Herder-Str. 3, D-79104 Freiburg, Germany
| | - Edoardo G Carnio
- Physikalisches Institut, Albert-Ludwigs-Universität Freiburg, Hermann-Herder-Str. 3, D-79104 Freiburg, Germany
| | - Vyacheslav N Shatokhin
- Physikalisches Institut, Albert-Ludwigs-Universität Freiburg, Hermann-Herder-Str. 3, D-79104 Freiburg, Germany
| |
Collapse
|
7
|
Ames B, Buchleitner A, Carnio EG, Shatokhin VN. Pulse area dependence of multiple quantum coherence signals in dilute thermal gases. J Chem Phys 2021; 155:044306. [PMID: 34340375 DOI: 10.1063/5.0053673] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
In the general framework of open quantum systems, we assess the impact of the pulse area on single and double quantum coherence (1QC and 2QC) signals extracted from fluorescence emitted by dilute thermal gases. We show that 1QC and 2QC signals are periodic functions of the pulse area, with distinctive features that reflect the particles' interactions via photon exchange, the polarizations of the laser pulses, and the observation direction.
Collapse
Affiliation(s)
- Benedikt Ames
- Physikalisches Institut, Albert-Ludwigs-Universität Freiburg, Hermann-Herder-Str. 3, D-79104 Freiburg, Germany
| | - Andreas Buchleitner
- Physikalisches Institut, Albert-Ludwigs-Universität Freiburg, Hermann-Herder-Str. 3, D-79104 Freiburg, Germany
| | - Edoardo G Carnio
- Physikalisches Institut, Albert-Ludwigs-Universität Freiburg, Hermann-Herder-Str. 3, D-79104 Freiburg, Germany
| | - Vyacheslav N Shatokhin
- Physikalisches Institut, Albert-Ludwigs-Universität Freiburg, Hermann-Herder-Str. 3, D-79104 Freiburg, Germany
| |
Collapse
|
8
|
Abstract
We investigate optimal states of photon pairs to excite a target transition in a multilevel quantum system. With the help of coherent control theory for two-photon absorption with quantum light, we infer the maximal population achievable by optimal entangled vs separable states of light. Interference between excitation pathways as well as the presence of nearby states may hamper the selective excitation of a particular target state, but we show that quantum correlations can help to overcome this problem and enhance the achievable "selectivity" between two energy levels, i.e., the relative difference in population transferred into each of them. We find that the added value of optimal entangled states of light increases with broadening linewidths of the target states.
Collapse
Affiliation(s)
- Edoardo G Carnio
- Physikalisches Institut, Albert-Ludwigs-Universität Freiburg, Hermann-Herder-Straße 3, D-79104 Freiburg, Germany
| | - Andreas Buchleitner
- Physikalisches Institut, Albert-Ludwigs-Universität Freiburg, Hermann-Herder-Straße 3, D-79104 Freiburg, Germany
| | - Frank Schlawin
- Max Planck Institute for the Structure and Dynamics of Matter, Luruper Chaussee 149, D-22761 Hamburg, Germany
| |
Collapse
|
9
|
Pausch L, Carnio EG, Rodríguez A, Buchleitner A. Chaos and Ergodicity across the Energy Spectrum of Interacting Bosons. Phys Rev Lett 2021; 126:150601. [PMID: 33929228 DOI: 10.1103/physrevlett.126.150601] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Revised: 01/20/2021] [Accepted: 02/24/2021] [Indexed: 06/12/2023]
Abstract
We identify the chaotic phase of the Bose-Hubbard Hamiltonian by the energy-resolved correlation between spectral features and structural changes of the associated eigenstates as exposed by their generalized fractal dimensions. The eigenvectors are shown to become ergodic in the thermodynamic limit, in the configuration space Fock basis, in which random matrix theory offers a remarkable description of their typical structure. The distributions of the generalized fractal dimensions, however, are ever more distinguishable from random matrix theory as the Hilbert space dimension grows.
Collapse
Affiliation(s)
- Lukas Pausch
- Physikalisches Institut, Albert-Ludwigs-Universität Freiburg, Hermann-Herder-Straße 3, D-79104 Freiburg, Germany
| | - Edoardo G Carnio
- Physikalisches Institut, Albert-Ludwigs-Universität Freiburg, Hermann-Herder-Straße 3, D-79104 Freiburg, Germany
- EUCOR Centre for Quantum Science and Quantum Computing, Albert-Ludwigs-Universität Freiburg, Hermann-Herder-Straße 3, D-79104 Freiburg, Germany
| | - Alberto Rodríguez
- Departamento de Física Fundamental, Universidad de Salamanca, E-37008 Salamanca, Spain
| | - Andreas Buchleitner
- Physikalisches Institut, Albert-Ludwigs-Universität Freiburg, Hermann-Herder-Straße 3, D-79104 Freiburg, Germany
- EUCOR Centre for Quantum Science and Quantum Computing, Albert-Ludwigs-Universität Freiburg, Hermann-Herder-Straße 3, D-79104 Freiburg, Germany
| |
Collapse
|
10
|
Schäfer F, Bastarrachea-Magnani MA, Lode AUJ, de Parny LDF, Buchleitner A. Spectral Structure and Many-Body Dynamics of Ultracold Bosons in a Double-Well. Entropy (Basel) 2020; 22:E382. [PMID: 33286153 PMCID: PMC7516856 DOI: 10.3390/e22040382] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Revised: 03/19/2020] [Accepted: 03/20/2020] [Indexed: 11/17/2022]
Abstract
We examine the spectral structure and many-body dynamics of two and three repulsively interacting bosons trapped in a one-dimensional double-well, for variable barrier height, inter-particle interaction strength, and initial conditions. By exact diagonalization of the many-particle Hamiltonian, we specifically explore the dynamical behavior of the particles launched either at the single-particle ground state or saddle-point energy, in a time-independent potential. We complement these results by a characterization of the cross-over from diabatic to quasi-adiabatic evolution under finite-time switching of the potential barrier, via the associated time evolution of a single particle's von Neumann entropy. This is achieved with the help of the multiconfigurational time-dependent Hartree method for indistinguishable particles (MCTDH-X)-which also allows us to extrapolate our results for increasing particle numbers.
Collapse
Affiliation(s)
- Frank Schäfer
- Physikalisches Institut, Albert-Ludwigs-Universität Freiburg, Hermann-Herder-Straße 3, D-79104 Freiburg, Germany; (M.A.B.-M.); (A.U.J.L.); (L.d.F.d.P.)
- Department of Physics, University of Basel, Klingelbergstrasse 82, CH-4056 Basel, Switzerland
| | - Miguel A. Bastarrachea-Magnani
- Physikalisches Institut, Albert-Ludwigs-Universität Freiburg, Hermann-Herder-Straße 3, D-79104 Freiburg, Germany; (M.A.B.-M.); (A.U.J.L.); (L.d.F.d.P.)
- Department of Physics and Astronomy, Aarhus University, Ny Munkegade, DK-8000 Aarhus C, Denmark
| | - Axel U. J. Lode
- Physikalisches Institut, Albert-Ludwigs-Universität Freiburg, Hermann-Herder-Straße 3, D-79104 Freiburg, Germany; (M.A.B.-M.); (A.U.J.L.); (L.d.F.d.P.)
| | - Laurent de Forges de Parny
- Physikalisches Institut, Albert-Ludwigs-Universität Freiburg, Hermann-Herder-Straße 3, D-79104 Freiburg, Germany; (M.A.B.-M.); (A.U.J.L.); (L.d.F.d.P.)
- ACRI-ST, 260 route du Pin Montard, 06904 Sophia Antipolis CEDEX, France
| | - Andreas Buchleitner
- Physikalisches Institut, Albert-Ludwigs-Universität Freiburg, Hermann-Herder-Straße 3, D-79104 Freiburg, Germany; (M.A.B.-M.); (A.U.J.L.); (L.d.F.d.P.)
- Freiburg Institute for Advanced Studies (FRIAS), Albert-Ludwigs-Universität Freiburg, Albertstr. 19, D-79104 Freiburg, Germany
| |
Collapse
|
11
|
Gebhart V, Snizhko K, Wellens T, Buchleitner A, Romito A, Gefen Y. Topological transition in measurement-induced geometric phases. Proc Natl Acad Sci U S A 2020; 117:5706-5713. [PMID: 32123099 PMCID: PMC7084105 DOI: 10.1073/pnas.1911620117] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The state of a quantum system, adiabatically driven in a cycle, may acquire a measurable phase depending only on the closed trajectory in parameter space. Such geometric phases are ubiquitous and also underline the physics of robust topological phenomena such as the quantum Hall effect. Equivalently, a geometric phase may be induced through a cyclic sequence of quantum measurements. We show that the application of a sequence of weak measurements renders the closed trajectories, hence the geometric phase, stochastic. We study the concomitant probability distribution and show that, when varying the measurement strength, the mapping between the measurement sequence and the geometric phase undergoes a topological transition. Our finding may impact measurement-induced control and manipulation of quantum states-a promising approach to quantum information processing. It also has repercussions on understanding the foundations of quantum measurement.
Collapse
Affiliation(s)
- Valentin Gebhart
- Physikalisches Institut, Albert-Ludwigs-Universität Freiburg, 79104 Freiburg, Germany
- Department of Condensed Matter Physics, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Kyrylo Snizhko
- Department of Condensed Matter Physics, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Thomas Wellens
- Physikalisches Institut, Albert-Ludwigs-Universität Freiburg, 79104 Freiburg, Germany
| | - Andreas Buchleitner
- Physikalisches Institut, Albert-Ludwigs-Universität Freiburg, 79104 Freiburg, Germany
| | - Alessandro Romito
- Department of Physics, Lancaster University, Lancaster LA1 4YB, United Kingdom
| | - Yuval Gefen
- Department of Condensed Matter Physics, Weizmann Institute of Science, Rehovot 76100, Israel;
| |
Collapse
|
12
|
Abstract
Stunning progress in the experimental resolution and control of natural or man-made complex systems at the level of their quantum mechanical constituents raises the question, across diverse subdisciplines of physics, chemistry, and biology, whether the fundamental quantum nature may condition the dynamical and functional system properties on mesoscopic if not macroscopic scales. However, which are the distinctive signatures of quantum properties in complex systems, notably when modulated by environmental stochasticity and dynamical instabilities? It appears that, to settle this question across the above communities, a shared understanding is needed of the central feature of quantum mechanics: wave-particle duality. In this Perspective, we elaborate how randomness induced by this very quantum property can be discerned from the stochasticity ubiquitous in complex systems already on the classical level. We argue that in the study of increasingly complex systems, such distinction requires the analysis of single incidents of quantum dynamical processes.
Collapse
Affiliation(s)
- Edoardo G Carnio
- Physikalisches Institut , Albert-Ludwigs-Universität Freiburg , Hermann-Herder-Str. 3 , 79104 Freiburg im Breisgau , Federal Republic of Germany
| | - Heinz-Peter Breuer
- Physikalisches Institut , Albert-Ludwigs-Universität Freiburg , Hermann-Herder-Str. 3 , 79104 Freiburg im Breisgau , Federal Republic of Germany
- Freiburg Institute for Advanced Studies (FRIAS) , Albert-Ludwigs-Universität Freiburg , Albertstr. 19 , 79104 Freiburg im Breisgau , Federal Republic of Germany
| | - Andreas Buchleitner
- Physikalisches Institut , Albert-Ludwigs-Universität Freiburg , Hermann-Herder-Str. 3 , 79104 Freiburg im Breisgau , Federal Republic of Germany
- Freiburg Institute for Advanced Studies (FRIAS) , Albert-Ludwigs-Universität Freiburg , Albertstr. 19 , 79104 Freiburg im Breisgau , Federal Republic of Germany
- Erwin Schrödinger International Institute for Mathematics and Physics , University of Vienna , Boltzmanngasse 9 , 1090 Vienna , Austria
| |
Collapse
|
13
|
Lindinger J, Buchleitner A, Rodríguez A. Many-Body Multifractality throughout Bosonic Superfluid and Mott Insulator Phases. Phys Rev Lett 2019; 122:106603. [PMID: 30932664 DOI: 10.1103/physrevlett.122.106603] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2018] [Indexed: 06/09/2023]
Abstract
We demonstrate many-body multifractality of the Bose-Hubbard Hamiltonian's ground state in Fock space, for arbitrary values of the interparticle interaction. Generalized fractal dimensions unambiguously signal, even for small system sizes, the emergence of a Mott insulator that cannot, however, be naively identified with a localized phase in Fock space. We show that the scaling of the derivative of any generalized fractal dimension with respect to the interaction strength encodes the critical point of the superfluid to the Mott insulator transition, and provides an efficient way to accurately estimate its position. We further establish that the transition can be quantitatively characterized by one single wave function amplitude from the exponentially large Fock space.
Collapse
Affiliation(s)
- Jakob Lindinger
- Physikalisches Institut, Albert-Ludwigs-Universität-Freiburg, Hermann-Herder-Straße 3, D-79104 Freiburg, Germany
| | - Andreas Buchleitner
- Physikalisches Institut, Albert-Ludwigs-Universität-Freiburg, Hermann-Herder-Straße 3, D-79104 Freiburg, Germany
| | - Alberto Rodríguez
- Physikalisches Institut, Albert-Ludwigs-Universität-Freiburg, Hermann-Herder-Straße 3, D-79104 Freiburg, Germany
| |
Collapse
|
14
|
Dittel C, Dufour G, Walschaers M, Weihs G, Buchleitner A, Keil R. Totally Destructive Many-Particle Interference. Phys Rev Lett 2018; 120:240404. [PMID: 29956991 DOI: 10.1103/physrevlett.120.240404] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2018] [Indexed: 06/08/2023]
Abstract
In a general, multimode scattering setup, we show how the permutation symmetry of a many-particle input state determines those scattering unitaries that exhibit strictly suppressed many-particle transition events. We formulate purely algebraic suppression laws that identify these events and show that the many-particle interference at their origin is robust under weak disorder and imperfect indistinguishability of the interfering particles. Finally, we demonstrate that all suppression laws so far described in the literature are embedded in the general framework that we here introduce.
Collapse
Affiliation(s)
- Christoph Dittel
- Institut für Experimentalphysik, Universität Innsbruck, Technikerstr. 25, 6020 Innsbruck, Austria
- Physikalisches Institut, Albert-Ludwigs-Universität Freiburg, Hermann-Herder-Str. 3, 79104 Freiburg, Germany
| | - Gabriel Dufour
- Physikalisches Institut, Albert-Ludwigs-Universität Freiburg, Hermann-Herder-Str. 3, 79104 Freiburg, Germany
- Freiburg Institute for Advanced Studies, Albert-Ludwigs-Universität-Freiburg, Albertstr. 19, 79104 Freiburg, Germany
| | - Mattia Walschaers
- Laboratoire Kastler Brossel, Sorbonne Université, CNRS, ENS-PSL Research University, Collège de France; 4 place Jussieu, F-75252 Paris, France
| | - Gregor Weihs
- Institut für Experimentalphysik, Universität Innsbruck, Technikerstr. 25, 6020 Innsbruck, Austria
| | - Andreas Buchleitner
- Physikalisches Institut, Albert-Ludwigs-Universität Freiburg, Hermann-Herder-Str. 3, 79104 Freiburg, Germany
| | - Robert Keil
- Institut für Experimentalphysik, Universität Innsbruck, Technikerstr. 25, 6020 Innsbruck, Austria
| |
Collapse
|
15
|
Brünner T, Dufour G, Rodríguez A, Buchleitner A. Signatures of Indistinguishability in Bosonic Many-Body Dynamics. Phys Rev Lett 2018; 120:210401. [PMID: 29883163 DOI: 10.1103/physrevlett.120.210401] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2017] [Indexed: 06/08/2023]
Abstract
The dynamics of bosons in generic multimode systems, such as Bose-Hubbard models, are not only determined by interactions among the particles, but also by their mutual indistinguishability manifested in many-particle interference. We introduce a measure of indistinguishability for Fock states of bosons whose mutual distinguishability is controlled by an internal degree of freedom. We demonstrate how this measure emerges both in the noninteracting and interacting evolution of observables. In particular, we find an unambiguous relationship between our measure and the variance of single-particle observables in the noninteracting limit. A nonvanishing interaction leads to a hierarchy of interaction-induced interference processes, such that even the expectation value of single-particle observables is influenced by the degree of indistinguishability.
Collapse
Affiliation(s)
- Tobias Brünner
- Physikalisches Institut, Albert-Ludwigs-Universität-Freiburg, Hermann-Herder-Straße 3, D-79104 Freiburg, Germany
| | - Gabriel Dufour
- Physikalisches Institut, Albert-Ludwigs-Universität-Freiburg, Hermann-Herder-Straße 3, D-79104 Freiburg, Germany
- Freiburg Institute for Advanced Studies, Albert-Ludwigs-Universität-Freiburg, Albertstraße 19, D-79104 Freiburg, Germany
| | - Alberto Rodríguez
- Physikalisches Institut, Albert-Ludwigs-Universität-Freiburg, Hermann-Herder-Straße 3, D-79104 Freiburg, Germany
| | - Andreas Buchleitner
- Physikalisches Institut, Albert-Ludwigs-Universität-Freiburg, Hermann-Herder-Straße 3, D-79104 Freiburg, Germany
| |
Collapse
|
16
|
Marzolino U, Buchleitner A. Performances and robustness of quantum teleportation with identical particles. Proc Math Phys Eng Sci 2016; 472:20150621. [PMID: 26997896 PMCID: PMC4786041 DOI: 10.1098/rspa.2015.0621] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2015] [Accepted: 12/22/2015] [Indexed: 11/12/2022] Open
Abstract
When quantum teleportation is performed with truly identical massive particles, indistinguishability allows us to teleport addressable degrees of freedom which do not identify particles, but, for example, orthogonal modes. The key resource of the protocol is a state of entangled modes, but the conservation of the total number of particles does not allow for perfect deterministic teleportation unless the number of particles in the resource state goes to infinity. Here, we study the convergence of teleportation performances in the above limit and provide sufficient conditions for asymptotic perfect teleportation. We also apply these conditions to the case of resource states affected by noise.
Collapse
Affiliation(s)
- Ugo Marzolino
- Univerza v Ljubljani, Jadranska 19, Ljubljana 1000, Slovenija
- Albert-Ludwigs-Universität Freiburg, Hermann-Herder-Straße 3, Freiburg 79104, Deutschland
| | - Andreas Buchleitner
- Albert-Ludwigs-Universität Freiburg, Hermann-Herder-Straße 3, Freiburg 79104, Deutschland
| |
Collapse
|
17
|
Carnio EG, Buchleitner A, Gessner M. Robust Asymptotic Entanglement under Multipartite Collective Dephasing. Phys Rev Lett 2015; 115:010404. [PMID: 26182085 DOI: 10.1103/physrevlett.115.010404] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2015] [Indexed: 06/04/2023]
Abstract
We derive an analytic solution for the ensemble-averaged collective dephasing dynamics of N noninteracting atoms in a fluctuating homogeneous external field. The obtained Kraus map is used to specify families of states whose entanglement properties are preserved at all times under arbitrary field orientations, even for states undergoing incoherent evolution. Our results apply to arbitrary spectral distributions of the field fluctuations.
Collapse
Affiliation(s)
- Edoardo G Carnio
- Physikalisches Institut, Albert-Ludwigs-Universität Freiburg, Hermann-Herder-Straße 3, 79104 Freiburg, Germany
- Department of Physics, University of Warwick, Coventry CV4 7AL, United Kingdom
| | - Andreas Buchleitner
- Physikalisches Institut, Albert-Ludwigs-Universität Freiburg, Hermann-Herder-Straße 3, 79104 Freiburg, Germany
- Freiburg Institute for Advanced Studies, Albert-Ludwigs-Universität Freiburg, Albertstraße 19, 79104 Freiburg, Germany
| | - Manuel Gessner
- Physikalisches Institut, Albert-Ludwigs-Universität Freiburg, Hermann-Herder-Straße 3, 79104 Freiburg, Germany
| |
Collapse
|
18
|
Gessner M, Schlawin F, Buchleitner A. Probing polariton dynamics in trapped ions with phase-coherent two-dimensional spectroscopy. J Chem Phys 2015; 142:212439. [PMID: 26049459 DOI: 10.1063/1.4919796] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We devise a phase-coherent three-pulse protocol to probe the polariton dynamics in a trapped-ion quantum simulation. In contrast to conventional nonlinear signals, the presented scheme does not change the number of excitations in the system, allowing for the investigation of the dynamics within an N-excitation manifold. In the particular case of a filling factor one (N excitations in an N-ion chain), the proposed interaction induces coherent transitions between a delocalized phonon superfluid and a localized atomic insulator phase. Numerical simulations of a two-ion chain demonstrate that the resulting two-dimensional spectra allow for the unambiguous identification of the distinct phases, and the two-dimensional line shapes efficiently characterize the relevant decoherence mechanism.
Collapse
Affiliation(s)
- Manuel Gessner
- Physikalisches Institut, Albert-Ludwigs-Universität Freiburg, Hermann-Herder-Straße 3, 79104 Freiburg, Germany
| | - Frank Schlawin
- Physikalisches Institut, Albert-Ludwigs-Universität Freiburg, Hermann-Herder-Straße 3, 79104 Freiburg, Germany
| | - Andreas Buchleitner
- Physikalisches Institut, Albert-Ludwigs-Universität Freiburg, Hermann-Herder-Straße 3, 79104 Freiburg, Germany
| |
Collapse
|
19
|
Zimmermann J, Mulet R, Scholes GD, Wellens T, Buchleitner A. Improving triplet-triplet-annihilation based upconversion systems by tuning their topological structure. J Chem Phys 2015; 141:184104. [PMID: 25399129 DOI: 10.1063/1.4901336] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Materials capable to perform upconversion of light transform the photon spectrum and can be used to increase the efficiency of solar cells by upconverting sub-bandgap photons, increasing the density of photons able to generate an electron-hole pair in the cell. Incoherent solar radiation suffices to activate upconverters based on sensitized triplet-triplet annihilation, which makes them particularly suited for this task. This process requires two molecular species, sensitizers absorbing low energy photons, and emitters generating higher frequency photons. Successful implementations exist in solutions and solids. However, solid upconverters exhibit lower efficiency than those in solution, which poses a serious problem for real applications. In the present work, we suggest a new strategy to increase the efficiency of sensitized upconverters that exploits the solid nature of the material. We show that an upconversion model system with molecules distributed as clusters outperforms a system with a random distribution of molecules, as used in current upconverters. Our simulations reveal a high potential for improvement of upconverter systems by exploring different structural configurations of the molecules. The implementation of advanced structures can push the performance of solid upconverters further towards the theoretical limit and a step closer to technological application of low power upconversion.
Collapse
Affiliation(s)
- Jochen Zimmermann
- Physikalisches Institut, Albert-Ludwigs-Universität Freiburg, Hermann-Herder-Str. 3, 79104 Freiburg, Germany
| | - Roberto Mulet
- Physikalisches Institut, Albert-Ludwigs-Universität Freiburg, Hermann-Herder-Str. 3, 79104 Freiburg, Germany
| | - Gregory D Scholes
- Physikalisches Institut, Albert-Ludwigs-Universität Freiburg, Hermann-Herder-Str. 3, 79104 Freiburg, Germany
| | - Thomas Wellens
- Physikalisches Institut, Albert-Ludwigs-Universität Freiburg, Hermann-Herder-Str. 3, 79104 Freiburg, Germany
| | - Andreas Buchleitner
- Physikalisches Institut, Albert-Ludwigs-Universität Freiburg, Hermann-Herder-Str. 3, 79104 Freiburg, Germany
| |
Collapse
|
20
|
Walschaers M, Mulet R, Wellens T, Buchleitner A. Statistical theory of designed quantum transport across disordered networks. Phys Rev E Stat Nonlin Soft Matter Phys 2015; 91:042137. [PMID: 25974468 DOI: 10.1103/physreve.91.042137] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2014] [Indexed: 06/04/2023]
Abstract
We explain how centrosymmetry, together with a dominant doublet of energy eigenstates in the local density of states, can guarantee interference-assisted, strongly enhanced, strictly coherent quantum excitation transport between two predefined sites of a random network of two-level systems. Starting from a generalization of the chaos-assisted tunnelling mechanism, we formulate a random matrix theoretical framework for the analytical prediction of the transfer time distribution, of lower bounds of the transfer efficiency, and of the scaling behavior of characteristic statistical properties with the size of the network. We show that these analytical predictions compare well to numerical simulations, using Hamiltonians sampled from the Gaussian orthogonal ensemble.
Collapse
Affiliation(s)
- Mattia Walschaers
- Physikalisches Institut, Albert-Ludwigs-Universität Freiburg, Hermann-Herder-Str. 3, D-79104 Freiburg, Germany
- Instituut voor Theoretische Fysica, University of Leuven, Celestijnenlaan 200D, B-3001 Heverlee, Belgium
| | - Roberto Mulet
- Physikalisches Institut, Albert-Ludwigs-Universität Freiburg, Hermann-Herder-Str. 3, D-79104 Freiburg, Germany
- Complex Systems Group, Department of Theoretical Physics, University of Havana, Cuba
| | - Thomas Wellens
- Physikalisches Institut, Albert-Ludwigs-Universität Freiburg, Hermann-Herder-Str. 3, D-79104 Freiburg, Germany
| | - Andreas Buchleitner
- Physikalisches Institut, Albert-Ludwigs-Universität Freiburg, Hermann-Herder-Str. 3, D-79104 Freiburg, Germany
- Freiburg Institute for Advanced Studies, Albert-Ludwigs-Universität Freiburg, Albertstr. 19, D-79104 Freiburg, Germany
| |
Collapse
|
21
|
Jörder F, Zimmermann K, Rodriguez A, Buchleitner A. Interaction effects on dynamical localization in driven helium. Phys Rev Lett 2014; 113:063004. [PMID: 25148324 DOI: 10.1103/physrevlett.113.063004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2013] [Indexed: 06/03/2023]
Abstract
Dynamical localization prevents driven atomic systems from fast fragmentation by hampering the excitation process. We present numerical simulations within a collinear model of microwave-driven helium Rydberg atoms and prove that dynamical localization survives the impact of electron-electron interaction, even for doubly excited states in the presence of fast autoionization. We conclude that the effect of electron-electron repulsion on localization can be described by an appropriate rescaling of the atomic level density and of the external field with the strength of the interaction.
Collapse
Affiliation(s)
- Felix Jörder
- Physikalisches Institut, Albert-Ludwigs-Universität Freiburg, Hermann-Herder-Straße 3, D-79104 Freiburg, Germany
| | - Klaus Zimmermann
- Physikalisches Institut, Albert-Ludwigs-Universität Freiburg, Hermann-Herder-Straße 3, D-79104 Freiburg, Germany
| | - Alberto Rodriguez
- Physikalisches Institut, Albert-Ludwigs-Universität Freiburg, Hermann-Herder-Straße 3, D-79104 Freiburg, Germany
| | - Andreas Buchleitner
- Physikalisches Institut, Albert-Ludwigs-Universität Freiburg, Hermann-Herder-Straße 3, D-79104 Freiburg, Germany
| |
Collapse
|
22
|
Tichy MC, Mayer K, Buchleitner A, Mølmer K. Stringent and efficient assessment of boson-sampling devices. Phys Rev Lett 2014; 113:020502. [PMID: 25062152 DOI: 10.1103/physrevlett.113.020502] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2013] [Indexed: 06/03/2023]
Abstract
Boson sampling holds the potential to experimentally falsify the extended Church-Turing thesis. The computational hardness of boson sampling, however, complicates the certification that an experimental device yields correct results in the regime in which it outmatches classical computers. To certify a boson sampler, one needs to verify quantum predictions and rule out models that yield these predictions without true many-boson interference. We show that a semiclassical model for many-boson propagation reproduces coarse-grained observables that are proposed as witnesses of boson sampling. A test based on Fourier matrices is demonstrated to falsify physically plausible alternatives to coherent many-boson propagation.
Collapse
Affiliation(s)
- Malte C Tichy
- Department of Physics and Astronomy, Aarhus University, DK-8000 Aarhus, Denmark
| | - Klaus Mayer
- Physikalisches Institut, Albert-Ludwigs-Universität Freiburg, D-79104 Freiburg, Germany
| | - Andreas Buchleitner
- Physikalisches Institut, Albert-Ludwigs-Universität Freiburg, D-79104 Freiburg, Germany
| | - Klaus Mølmer
- Department of Physics and Astronomy, Aarhus University, DK-8000 Aarhus, Denmark
| |
Collapse
|
23
|
Walschaers M, Diaz JFDC, Mulet R, Buchleitner A. Optimally designed quantum transport across disordered networks. Phys Rev Lett 2013; 111:180601. [PMID: 24237498 DOI: 10.1103/physrevlett.111.180601] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2013] [Indexed: 06/02/2023]
Abstract
We establish a general mechanism for highly efficient quantum transport through finite, disordered 3D networks. It relies on the interplay of disorder with centrosymmetry and a dominant doublet spectral structure and can be controlled by the proper tuning of only coarse-grained quantities. Photosynthetic light harvesting complexes are discussed as potential biological incarnations of this design principle.
Collapse
Affiliation(s)
- Mattia Walschaers
- Physikalisches Institut, Albert-Ludwigs-Universitat Freiburg, Hermann-Herder-Strasse 3, D-79104 Freiburg, Germany and Instituut voor Theoretische Fysica, KU Leuven, Celestijnenlaan 200D, B-3001 Heverlee, Belgium
| | | | | | | |
Collapse
|
24
|
Ra YS, Tichy MC, Lim HT, Kwon O, Mintert F, Buchleitner A, Kim YH. Observation of detection-dependent multi-photon coherence times. Nat Commun 2013; 4:2451. [DOI: 10.1038/ncomms3451] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2013] [Accepted: 08/15/2013] [Indexed: 11/09/2022] Open
|
25
|
Abstract
We study to what extent the detrimental impact of dissipation on quantum properties can be compensated by suitable coherent dynamics. To this end, we develop a general method to determine the control Hamiltonian that optimally counteracts a given dissipation mechanism, in order to sustain the desired property, and apply it to two exemplary target properties: the coherence of a decaying two-level system and the entanglement of two qubits in the presence of local dissipation.
Collapse
Affiliation(s)
- Simeon Sauer
- Physikalisches Institut, Albert-Ludwigs-Universität Freiburg, Hermann-Herder-Strasse 3, D-79104 Freiburg, Germany
| | | | | |
Collapse
|
26
|
Zimmermann J, Mulet R, Wellens T, Scholes GD, Buchleitner A. Efficiency scaling of non-coherent upconversion in a one-dimensional model system. J Chem Phys 2013; 138:134505. [PMID: 23574242 DOI: 10.1063/1.4798406] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
A very promising approach to obtain efficient upconversion of light is the use of triplet-triplet annihilation of excitations in molecular systems. In real materials, besides upconversion, many other physical processes take place--fluorescence, phosphorescence, non-radiative decay, annihilation, diffusion--and compete with upconversion. The main objective of this work is to design a proof of principle model that can be used to shed light on the interplay between these processes. Ultimately, we want to establish general principles that may guide experimentalists toward the design of solid state materials with maximum efficiency. Here we show, in a one-dimensional model system, that upconversion can be optimized by varying the ratio between the two molecular species used in triplet-triplet-annihilation based upconversion systems, even in the presence of undesired losses through phosphorescence, non-radiative decay, or annihilation. We derive scaling laws for this ratio and for the maximum efficiency of upconversion, as a function of the diffusion rate J, as well as of the creation and of the decay rate of the excitations.
Collapse
Affiliation(s)
- Jochen Zimmermann
- Physikalisches Institut, Albert-Ludwigs-Universität Freiburg, Hermann-Herder-Str. 3, 79104 Freiburg, Germany.
| | | | | | | | | |
Collapse
|
27
|
Geiger T, Wellens T, Buchleitner A. Inelastic multiple scattering of interacting bosons in weak random potentials. Phys Rev Lett 2012; 109:030601. [PMID: 22861833 DOI: 10.1103/physrevlett.109.030601] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2012] [Indexed: 06/01/2023]
Abstract
We develop a diagrammatic scattering theory for interacting bosons in a three-dimensional, weakly disordered potential. We show how collisional energy transfer between the bosons induces the thermalization of the inelastic single-particle current which, after only a few collision events, dominates over the elastic contribution described by the Gross-Pitaevskii ansatz.
Collapse
Affiliation(s)
- Tobias Geiger
- Physikalisches Institut, Albert-Ludwigs-Universität Freiburg, D-79104 Freiburg, Germany
| | | | | |
Collapse
|
28
|
Scholak T, de Melo F, Wellens T, Mintert F, Buchleitner A. Efficient and coherent excitation transfer across disordered molecular networks. Phys Rev E Stat Nonlin Soft Matter Phys 2011; 83:021912. [PMID: 21405868 DOI: 10.1103/physreve.83.021912] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2010] [Revised: 11/16/2010] [Indexed: 05/30/2023]
Abstract
We show that finite-size, disordered molecular networks can mediate highly efficient, coherent excitation transfer which is robust against ambient dephasing and associated with strong multisite entanglement. Such optimal, random molecular conformations may explain efficient energy transfer in the photosynthetic Fenna-Matthews-Olson complex.
Collapse
Affiliation(s)
- Torsten Scholak
- Physikalisches Institut, Albert-Ludwigs-Universität Freiburg, Hermann-Herder-Strasse 3, D-79104 Freiburg, Germany
| | | | | | | | | |
Collapse
|
29
|
Viviescas C, Guevara I, Carvalho ARR, Busse M, Buchleitner A. Entanglement dynamics in open two-qubit systems via diffusive quantum trajectories. Phys Rev Lett 2010; 105:210502. [PMID: 21231276 DOI: 10.1103/physrevlett.105.210502] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2010] [Indexed: 05/30/2023]
Abstract
We use quantum diffusive trajectories to prove that the time evolution of two-qubit entanglement under spontaneous emission can be fully characterized by optimal continuous monitoring. We analytically determine this optimal unraveling and derive a deterministic evolution equation for the system's concurrence. Furthermore, we propose an experiment to monitor the entanglement dynamics in bipartite two-level systems and to determine the disentanglement time from a single trajectory.
Collapse
Affiliation(s)
- Carlos Viviescas
- Departamento de Física, Universidad Nacional de Colombia, Carrera 30 No. 45-03 Edificio 404, Bogotá D.C., Colombia
| | | | | | | | | |
Collapse
|
30
|
|
31
|
Abstract
We construct time-dependent optimal control pulses based on a multipartite entanglement measure as the target functional. The control Hamiltonian is given purely algebraically and drives a composite quantum system rapidly into a highly entangled state that is robust against decoherence.
Collapse
Affiliation(s)
- Felix Platzer
- Physikalisches Institut, Albert-Ludwigs-Universität Freiburg, Hermann-Herder-Strasse 3, D-79104 Freiburg, Germany
| | | | | |
Collapse
|
32
|
Tichy MC, Tiersch M, de Melo F, Mintert F, Buchleitner A. Zero-transmission law for multiport beam splitters. Phys Rev Lett 2010; 104:220405. [PMID: 20867153 DOI: 10.1103/physrevlett.104.220405] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2010] [Indexed: 05/29/2023]
Abstract
The Hong-Ou-Mandel effect is generalized to a configuration of n bosons prepared in the n input ports of a Bell multiport beam splitter. We derive a strict suppression law for most possible output events, consistent with a generic bosonic behavior after suitable coarse graining.
Collapse
Affiliation(s)
- Malte Christopher Tichy
- Physikalisches Institut, Albert-Ludwigs-Universität Freiburg, Hermann-Herder-Strasse 3, D-79104 Freiburg, Germany
| | | | | | | | | |
Collapse
|
33
|
Schelle A, Delande D, Buchleitner A. Microwave-driven atoms: from Anderson localization to Einstein's photoeffect. Phys Rev Lett 2009; 102:183001. [PMID: 19518866 DOI: 10.1103/physrevlett.102.183001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2008] [Indexed: 05/27/2023]
Abstract
We study the counterpart of Anderson localization in driven one-electron Rydberg atoms. By changing the initial Rydberg state at fixed microwave frequency and interaction time, we numerically monitor the crossover from Anderson localization to the photoeffect in the atomic ionization signal.
Collapse
Affiliation(s)
- Alexej Schelle
- Physikalisches Institut der Albert-Ludwigs-Universität, Hermann-Herder-Strasse 3, D-79104 Freiburg, Germany
| | | | | |
Collapse
|
34
|
Venzl H, Daley AJ, Mintert F, Buchleitner A. Statistics of Schmidt coefficients and the simulability of complex quantum systems. Phys Rev E Stat Nonlin Soft Matter Phys 2009; 79:056223. [PMID: 19518552 DOI: 10.1103/physreve.79.056223] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/27/2008] [Revised: 02/18/2009] [Indexed: 05/27/2023]
Abstract
We show that the transition from regular to chaotic spectral statistics in interacting many-body quantum systems has an unambiguous signature in the distribution of Schmidt coefficients dynamically generated from a generic initial state, and thus limits the efficiency of the time-dependent density-matrix renormalization-group algorithm. We investigate this mechanism on the tilted Bose-Hubbard model; however the emergence of universal spectral properties allows translation of our conclusions to generic many-body quantum systems.
Collapse
Affiliation(s)
- Hannah Venzl
- Physikalisches Institut, Albert-Ludwigs-Universität Freiburg, Hermann-Herder-Str. 3, D-79104 Freiburg, Germany
| | | | | | | |
Collapse
|
35
|
Schmid C, Kiesel N, Wieczorek W, Weinfurter H, Mintert F, Buchleitner A. Experimental direct observation of mixed state entanglement. Phys Rev Lett 2008; 101:260505. [PMID: 19437629 DOI: 10.1103/physrevlett.101.260505] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
We report on the direct estimation of concurrence for mixed quantum states. The used method relies on joint measurements on two copies of an entangled state. In the experimental demonstration two polarization-entangled photon pairs emitted from spontaneous parametric down-conversion are analyzed together using a linear optics controlled phase gate. We demonstrate that the measured data, without need for further numerical processing, directly yield reliable estimates, despite experimental imperfections.
Collapse
Affiliation(s)
- Christian Schmid
- Max-Planck-Institute of Quantum Optics, Hans-Kopfermann-Strasse 1, 85748 Garching, Germany
| | | | | | | | | | | |
Collapse
|
36
|
Abstract
We provide a relation which describes how the entanglement of two d-level systems evolves as either system undergoes an arbitrary physical process. The dynamics of the entanglement turns out to be of a simple form and is fully captured by a single quantity.
Collapse
Affiliation(s)
- Markus Tiersch
- Physikalisches Institut, Albert-Ludwigs-Universität Freiburg, Hermann-Herder-Strasse 3, Freiburg, Germany.
| | | | | |
Collapse
|
37
|
Carvalho ARR, Busse M, Brodier O, Viviescas C, Buchleitner A. Optimal dynamical characterization of entanglement. Phys Rev Lett 2007; 98:190501. [PMID: 17677610 DOI: 10.1103/physrevlett.98.190501] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2006] [Indexed: 05/16/2023]
Abstract
We show that, for experimentally relevant systems, there is an optimal measurement strategy to monitor the time evolution of entanglement under open system dynamics. This suggests an efficient, dynamical characterization of the entanglement of composite, open quantum systems.
Collapse
Affiliation(s)
- André R R Carvalho
- Max-Planck-Institut für Physik komplexer Systeme, Nöthnitzer Strasse 38, 01187 Dresden, Germany
| | | | | | | | | |
Collapse
|
38
|
Abstract
We quantify an unknown mixed quantum state's entanglement by suitable, local parity measurements on its twofold copy. The associated observable qualifies as a generalized entanglement witness.
Collapse
Affiliation(s)
- Florian Mintert
- Department of Physics, Harvard University, 17 Oxford Street, Cambridge Massachusetts, USA
| | | |
Collapse
|
39
|
García-Mata I, Carvalho ARR, Mintert F, Buchleitner A. Entanglement screening by nonlinear resonances. Phys Rev Lett 2007; 98:120504. [PMID: 17501106 DOI: 10.1103/physrevlett.98.120504] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2006] [Indexed: 05/15/2023]
Abstract
We show that nonlinear resonances in a classically mixed phase space allow us to define generic, strongly entangled multipartite quantum states. The robustness of their multipartite entanglement increases with the particle number, i.e., in the semiclassical limit, for those classes of diffusive noise which assist the quantum-classical transition.
Collapse
Affiliation(s)
- Ignacio García-Mata
- Laboratoire de Physique Théorique, UMR 5152 du CNRS, Université Paul Sabatier, 31062 Toulouse Cedex 4, France.
| | | | | | | |
Collapse
|
40
|
Wimberger S, Schlagheck P, Eltschka C, Buchleitner A. Resonance-assisted decay of nondispersive wave packets. Phys Rev Lett 2006; 97:043001. [PMID: 16907569 DOI: 10.1103/physrevlett.97.043001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/24/2006] [Indexed: 05/11/2023]
Abstract
We present a quantitative semiclassical theory for the decay of nondispersive electronic wave packets in driven, ionizing Rydberg systems. Statistically robust quantities are extracted combining resonance-assisted tunneling with subsequent transport across chaotic phase space and a final ionization step.
Collapse
Affiliation(s)
- Sandro Wimberger
- CNR-INFM and Dipartimento di Fisica E. Fermi, Unversità degli Studi di Pisa, Largo Pontecorvo 3, 56127 Pisa, Italy
| | | | | | | |
Collapse
|
41
|
Buchleitner A, d'Arcy MB, Fishman S, Gardiner SA, Guarneri I, Ma ZY, Rebuzzini L, Summy GS. Quantum accelerator modes from the Farey tree. Phys Rev Lett 2006; 96:164101. [PMID: 16712235 DOI: 10.1103/physrevlett.96.164101] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2005] [Indexed: 05/09/2023]
Abstract
We show that mode locking finds a purely quantum nondissipative counterpart in atom-optical quantum accelerator modes. These modes are formed by exposing cold atoms to periodic kicks in the direction of the gravitational field. They are anchored to generalized Arnol'd tongues, parameter regions where driven nonlinear classical systems exhibit mode locking. A hierarchy for the rational numbers known as the Farey tree provides an ordering of the Arnol'd tongues and hence of experimentally observed accelerator modes.
Collapse
Affiliation(s)
- A Buchleitner
- Max-Planck-Institut für Physik komplexer Systeme, D-01187 Dresden, Germany
| | | | | | | | | | | | | | | |
Collapse
|
42
|
Walborn SP, Souto Ribeiro PH, Davidovich L, Mintert F, Buchleitner A. Experimental determination of entanglement with a single measurement. Nature 2006; 440:1022-4. [PMID: 16625190 DOI: 10.1038/nature04627] [Citation(s) in RCA: 263] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2005] [Accepted: 01/27/2006] [Indexed: 11/09/2022]
Abstract
Nearly all protocols requiring shared quantum information--such as quantum teleportation or key distribution--rely on entanglement between distant parties. However, entanglement is difficult to characterize experimentally. All existing techniques for doing so, including entanglement witnesses or Bell inequalities, disclose the entanglement of some quantum states but fail for other states; therefore, they cannot provide satisfactory results in general. Such methods are fundamentally different from entanglement measures that, by definition, quantify the amount of entanglement in any state. However, these measures suffer from the severe disadvantage that they typically are not directly accessible in laboratory experiments. Here we report a linear optics experiment in which we directly observe a pure-state entanglement measure, namely concurrence. Our measurement set-up includes two copies of a quantum state: these 'twin' states are prepared in the polarization and momentum degrees of freedom of two photons, and concurrence is measured with a single, local measurement on just one of the photons.
Collapse
Affiliation(s)
- S P Walborn
- Instituto de Física, Universidade Federal do Rio de Janeiro, Caixa Postal 68528, Rio de Janeiro, RJ 21941-972, Brazil.
| | | | | | | | | |
Collapse
|
43
|
Ponomarev AV, Madroñero J, Kolovsky AR, Buchleitner A. Atomic current across an optical lattice. Phys Rev Lett 2006; 96:050404. [PMID: 16486908 DOI: 10.1103/physrevlett.96.050404] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/23/2005] [Indexed: 05/06/2023]
Abstract
We devise a microscopic model for the emergence of a collision-induced, fermionic atomic current across a tilted optical lattice. Tuning the--experimentally controllable--parameters of the microscopic dynamics allows us to switch from Ohmic to negative differential conductance.
Collapse
Affiliation(s)
- Alexey V Ponomarev
- Max-Planck-Institut für Physik komplexer Systeme, Nöthnitzer Strasse 38, 01187 Dresden, Germany
| | | | | | | |
Collapse
|
44
|
Mintert F, Kuś M, Buchleitner A. Concurrence of mixed multipartite quantum States. Phys Rev Lett 2005; 95:260502. [PMID: 16486325 DOI: 10.1103/physrevlett.95.260502] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2004] [Revised: 04/08/2005] [Indexed: 05/06/2023]
Abstract
We propose generalizations of concurrence for multipartite quantum systems that can distinguish qualitatively distinct quantum correlations. All introduced quantities can be evaluated efficiently for arbitrary mixed sates.
Collapse
Affiliation(s)
- Florian Mintert
- Max-Planck-Institut für Physik komplexer Systeme, Dresden, Germany
| | | | | |
Collapse
|
45
|
Madroñero J, Buchleitner A. Ericson fluctuations in an open deterministic quantum system: theory meets experiment. Phys Rev Lett 2005; 95:263601. [PMID: 16486352 DOI: 10.1103/physrevlett.95.263601] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2005] [Indexed: 05/06/2023]
Abstract
We provide numerically exact photoexcitation cross sections of rubidium Rydberg states in crossed, static electric, and magnetic fields, in quantitative agreement with recent experimental results. Their spectral backbone underpins a clear transition towards the Ericson regime, associated with a universal, fluctuating behavior of the cross section of strongly coupled, fragmenting quantum systems.
Collapse
Affiliation(s)
- Javier Madroñero
- Max-Planck-Institut für Physik komplexer Systeme, Dresden, Germany
| | | |
Collapse
|
46
|
Shatokhin V, Müller CA, Buchleitner A. Coherent inelastic backscattering of intense laser light by cold atoms. Phys Rev Lett 2005; 94:043603. [PMID: 15783558 DOI: 10.1103/physrevlett.94.043603] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/27/2004] [Indexed: 05/24/2023]
Abstract
We present a nonperturbative treatment of coherent backscattering of intense laser light from cold atoms and predict a nonvanishing backscattering signal even at very large intensities, due to the constructive (self-)interference of inelastically scattered photons.
Collapse
Affiliation(s)
- V Shatokhin
- BI Stepanov Institute of Physics, National Academy of Sciences of Belarus, Skaryna Avenue 70, BY-220072 Minsk, Belarus
| | | | | |
Collapse
|
47
|
Abstract
We study the dynamics of multipartite entanglement under the influence of decoherence. A suitable generalization of concurrence reveals distinct scaling of the entanglement decay rate of Greenberger-Horne-Zeilinger and W states, for various environments.
Collapse
Affiliation(s)
- André R R Carvalho
- Max-Planck-Institut für Physik komplexer Systeme, Nöthnitzer Strasse 38, D-01187 Dresden, Germany
| | | | | |
Collapse
|
48
|
Abstract
We show that heating of harmonically trapped ions by periodic delta kicks is dramatically enhanced at isolated values of the Lamb-Dicke parameter. At these values, quasienergy eigenstates localized on island structures undergo avoided crossings with extended web states.
Collapse
Affiliation(s)
- André R R Carvalho
- Max-Planck-Institut für Physik komplexer Systeme, Nöthnitzer Strasse 38, D-01187 Dresden, Germany
| | | |
Collapse
|
49
|
Mintert F, Kuś M, Buchleitner A. Concurrence of mixed bipartite quantum states in arbitrary dimensions. Phys Rev Lett 2004; 92:167902. [PMID: 15169261 DOI: 10.1103/physrevlett.92.167902] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2003] [Indexed: 05/24/2023]
Abstract
We derive a lower bound for the concurrence of mixed bipartite quantum states, valid in arbitrary dimensions. As a corollary, a weaker, purely algebraic estimate is found, which detects mixed entangled states with a positive partial transpose.
Collapse
Affiliation(s)
- Florian Mintert
- Max-Planck-Institut für Physik Komplexer Systeme, Nöthnitzerstrasse 38, D-01187 Dresden, Germany
| | | | | |
Collapse
|
50
|
D'Arcy MB, Godun RM, Summy GS, Guarneri I, Wimberger S, Fishman S, Buchleitner A. Decoherence as a probe of coherent quantum dynamics. Phys Rev E Stat Nonlin Soft Matter Phys 2004; 69:027201. [PMID: 14995591 DOI: 10.1103/physreve.69.027201] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2003] [Indexed: 05/24/2023]
Abstract
The effect of decoherence, induced by spontaneous emission, on the dynamics of cold atoms periodically kicked by an optical lattice is experimentally and theoretically studied. Ideally, the mean energy growth is essentially unaffected by weak decoherence, but the resonant momentum distributions are fundamentally altered. It is shown that experiments are inevitably sensitive to certain nontrivial features of these distributions, in a way that explains the puzzle of the observed enhancement of resonances by decoherence [Phys. Rev. Lett. 87, 074102 (2001)]. This clarifies both the nature of the coherent evolution, and the way in which decoherence disrupts it.
Collapse
Affiliation(s)
- Michael B D'Arcy
- Clarendon Laboratory, Department of Physics, University of Oxford, Parks Road, Oxford OX1 3PU, United Kingdom
| | | | | | | | | | | | | |
Collapse
|