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Maksimov DN, Aksenov SV, Kolovsky AR. Non-Markovian master equation for quantum transport of fermionic carriers. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2023; 36:045301. [PMID: 37832566 DOI: 10.1088/1361-648x/ad0351] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Accepted: 10/13/2023] [Indexed: 10/15/2023]
Abstract
We propose a simple, yet feasible, model for quantum transport of fermionic carriers across tight-binding chain connecting two reservoirs maintained at arbitrary temperatures and chemical potentials. The model allows for elementary derivation of the master equation for the reduced single particle density matrix (SPDM) in a closed form in both Markov and Born approximations. In the Markov approximation the master equation is solved analytically, whereas in the Born approximation the problem is reduced to an algebraic equation for the SPDM in the Redfield form. The non-Markovian equation is shown to lead to resonant transport similar to Landauer's conductance. It is shown that in the deep non-Markovian regime the transport current can be matched with that obtained by the non-equilibrium Green's function method.
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Affiliation(s)
- D N Maksimov
- IRC SQC, Siberian Federal University, 660041 Krasnoyarsk, Russia
- Kirensky Institute of Physics, Federal Research Center KSC SB RAS, 660036 Krasnoyarsk, Russia
| | - S V Aksenov
- Kirensky Institute of Physics, Federal Research Center KSC SB RAS, 660036 Krasnoyarsk, Russia
| | - A R Kolovsky
- Kirensky Institute of Physics, Federal Research Center KSC SB RAS, 660036 Krasnoyarsk, Russia
- School of Engineering Physics and Radio Electronics, Siberian Federal University, 660041 Krasnoyarsk, Russia
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2
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Barresi A, Boulet A, Magierski P, Wlazłowski G. Dissipative Dynamics of Quantum Vortices in Fermionic Superfluid. PHYSICAL REVIEW LETTERS 2023; 130:043001. [PMID: 36763425 DOI: 10.1103/physrevlett.130.043001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Revised: 11/08/2022] [Accepted: 01/05/2023] [Indexed: 06/18/2023]
Abstract
In a recent article, Kwon et al. [Nature (London) 600, 64 (2021)NATUAS0028-083610.1038/s41586-021-04047-4] revealed nonuniversal dissipative dynamics of quantum vortices in a fermionic superfluid. The enhancement of the dissipative process is pronounced for the Bardeen-Cooper-Schrieffer interaction regime, and it was suggested that the effect is due to the presence of quasiparticles localized inside the vortex core. We test this hypothesis through numerical simulations with time-dependent density-functional theory: a fully microscopic framework with fermionic degrees of freedom. The results of fully microscopic calculations expose the impact of the vortex-bound states on dissipative dynamics in a fermionic superfluid. Their contribution is too weak to explain the experimental measurements, and we identify that thermal effects, giving rise to mutual friction between superfluid and the normal component, dominate the observed dynamics.
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Affiliation(s)
- Andrea Barresi
- Faculty of Physics, Warsaw University of Technology, Ulica Koszykowa 75, 00-662 Warsaw, Poland
| | - Antoine Boulet
- Faculty of Physics, Warsaw University of Technology, Ulica Koszykowa 75, 00-662 Warsaw, Poland
| | - Piotr Magierski
- Faculty of Physics, Warsaw University of Technology, Ulica Koszykowa 75, 00-662 Warsaw, Poland
- Department of Physics, University of Washington, Seattle, Washington 98195-1560, USA
| | - Gabriel Wlazłowski
- Faculty of Physics, Warsaw University of Technology, Ulica Koszykowa 75, 00-662 Warsaw, Poland
- Department of Physics, University of Washington, Seattle, Washington 98195-1560, USA
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3
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Wlazłowski G, Xhani K, Tylutki M, Proukakis NP, Magierski P. Dissipation Mechanisms in Fermionic Josephson Junction. PHYSICAL REVIEW LETTERS 2023; 130:023003. [PMID: 36706420 DOI: 10.1103/physrevlett.130.023003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Revised: 10/10/2022] [Accepted: 12/12/2022] [Indexed: 06/18/2023]
Abstract
We characterize numerically the dominant dynamical regimes in a superfluid ultracold fermionic Josephson junction. Beyond the coherent Josephson plasma regime, we discuss the onset and physical mechanism of dissipation due to the superflow exceeding a characteristic speed, and provide clear evidence distinguishing its physical mechanism across the weakly and strongly interacting limits, despite qualitative dynamics of global characteristics being only weakly sensitive to the operating dissipative mechanism. Specifically, dissipation in the strongly interacting regime occurs through the phase-slippage process, caused by the emission and propagation of quantum vortices, and sound waves-similar to the Bose-Einstein condensation limit. Instead, in the weak interaction limit, the main dissipative channel arises through the pair-breaking mechanism.
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Affiliation(s)
- Gabriel Wlazłowski
- Faculty of Physics, Warsaw University of Technology, Ulica Koszykowa 75, 00-662 Warsaw, Poland
- Department of Physics, University of Washington, Seattle, Washington 98195-1560, USA
| | - Klejdja Xhani
- Istituto Nazionale di Ottica del Consiglio Nazionale delle Ricerche (CNR-INO), 50019 Sesto Fiorentino, Italy
| | - Marek Tylutki
- Faculty of Physics, Warsaw University of Technology, Ulica Koszykowa 75, 00-662 Warsaw, Poland
| | - Nikolaos P Proukakis
- Joint Quantum Centre (JQC) Durham-Newcastle, School of Mathematics, Statistics and Physics, Newcastle University, Newcastle upon Tyne NE1 7RU, United Kingdom
| | - Piotr Magierski
- Faculty of Physics, Warsaw University of Technology, Ulica Koszykowa 75, 00-662 Warsaw, Poland
- Department of Physics, University of Washington, Seattle, Washington 98195-1560, USA
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Kwon WJ, Del Pace G, Xhani K, Galantucci L, Muzi Falconi A, Inguscio M, Scazza F, Roati G. Sound emission and annihilations in a programmable quantum vortex collider. Nature 2021; 600:64-69. [PMID: 34853459 DOI: 10.1038/s41586-021-04047-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Accepted: 09/22/2021] [Indexed: 11/09/2022]
Abstract
In quantum fluids, the quantization of circulation forbids the diffusion of a vortex swirling flow seen in classical viscous fluids. Yet, accelerating quantum vortices may lose their energy into acoustic radiations1,2, similar to the way electric charges decelerate on emitting photons. The dissipation of vortex energy underlies central problems in quantum hydrodynamics3, such as the decay of quantum turbulence, highly relevant to systems as varied as neutron stars, superfluid helium and atomic condensates4,5. A deep understanding of the elementary mechanisms behind irreversible vortex dynamics has been a goal for decades3,6, but it is complicated by the shortage of conclusive experimental signatures7. Here we address this challenge by realizing a programmable vortex collider in a planar, homogeneous atomic Fermi superfluid with tunable inter-particle interactions. We create on-demand vortex configurations and monitor their evolution, taking advantage of the accessible time and length scales of ultracold Fermi gases8,9. Engineering collisions within and between vortex-antivortex pairs allows us to decouple relaxation of the vortex energy due to sound emission and that due to interactions with normal fluid (that is, mutual friction). We directly visualize how the annihilation of vortex dipoles radiates a sound pulse. Further, our few-vortex experiments extending across different superfluid regimes reveal non-universal dissipative dynamics, suggesting that fermionic quasiparticles localized inside the vortex core contribute significantly to dissipation, thereby opening the route to exploring new pathways for quantum turbulence decay, vortex by vortex.
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Affiliation(s)
- W J Kwon
- European Laboratory for Nonlinear Spectroscopy (LENS), Sesto Fiorentino, Italy. .,Istituto Nazionale di Ottica del Consiglio Nazionale delle Ricerche (CNR-INO), Sesto Fiorentino, Italy.
| | - G Del Pace
- European Laboratory for Nonlinear Spectroscopy (LENS), Sesto Fiorentino, Italy.,Istituto Nazionale di Ottica del Consiglio Nazionale delle Ricerche (CNR-INO), Sesto Fiorentino, Italy
| | - K Xhani
- European Laboratory for Nonlinear Spectroscopy (LENS), Sesto Fiorentino, Italy.,Istituto Nazionale di Ottica del Consiglio Nazionale delle Ricerche (CNR-INO), Sesto Fiorentino, Italy
| | - L Galantucci
- Joint Quantum Centre (JQC) Durham-Newcastle, School of Mathematics, Statistics and Physics, Newcastle University, Newcastle upon Tyne, UK
| | - A Muzi Falconi
- European Laboratory for Nonlinear Spectroscopy (LENS), Sesto Fiorentino, Italy.,Istituto Nazionale di Ottica del Consiglio Nazionale delle Ricerche (CNR-INO), Sesto Fiorentino, Italy
| | - M Inguscio
- European Laboratory for Nonlinear Spectroscopy (LENS), Sesto Fiorentino, Italy.,Istituto Nazionale di Ottica del Consiglio Nazionale delle Ricerche (CNR-INO), Sesto Fiorentino, Italy.,Department of Engineering, Campus Bio-Medico University of Rome, Rome, Italy
| | - F Scazza
- European Laboratory for Nonlinear Spectroscopy (LENS), Sesto Fiorentino, Italy.,Istituto Nazionale di Ottica del Consiglio Nazionale delle Ricerche (CNR-INO), Sesto Fiorentino, Italy.,Department of Physics, University of Trieste, Trieste, Italy
| | - G Roati
- European Laboratory for Nonlinear Spectroscopy (LENS), Sesto Fiorentino, Italy.,Istituto Nazionale di Ottica del Consiglio Nazionale delle Ricerche (CNR-INO), Sesto Fiorentino, Italy
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Del Pace G, Kwon WJ, Zaccanti M, Roati G, Scazza F. Tunneling Transport of Unitary Fermions across the Superfluid Transition. PHYSICAL REVIEW LETTERS 2021; 126:055301. [PMID: 33605753 DOI: 10.1103/physrevlett.126.055301] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Accepted: 01/12/2021] [Indexed: 06/12/2023]
Abstract
We investigate the transport of a Fermi gas with unitarity-limited interactions across the superfluid phase transition, probing its response to a direct current (dc) drive through a tunnel junction. As the superfluid critical temperature is crossed from below, we observe the evolution from a highly nonlinear to an Ohmic conduction characteristic, associated with the critical breakdown of the Josephson dc current induced by pair condensate depletion. Moreover, we reveal a large and dominant anomalous contribution to resistive currents, which reaches its maximum at the lowest attained temperature, fostered by the tunnel coupling between the condensate and phononic Bogoliubov-Anderson excitations. Increasing the temperature, while the zeroing of supercurrents marks the transition to the normal phase, the conductance drops considerably but remains much larger than that of a normal, uncorrelated Fermi gas tunneling through the same junction. We attribute such enhanced transport to incoherent tunneling of sound modes, which remain weakly damped in the collisional hydrodynamic fluid of unpaired fermions at unitarity.
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Affiliation(s)
- G Del Pace
- Department of Physics and Astronomy, University of Florence, 50019 Sesto Fiorentino, Italy
- European Laboratory for Nonlinear Spectroscopy (LENS), 50019 Sesto Fiorentino, Italy
- Istituto Nazionale di Ottica del Consiglio Nazionale delle Ricerche (CNR-INO), 50019 Sesto Fiorentino, Italy
| | - W J Kwon
- European Laboratory for Nonlinear Spectroscopy (LENS), 50019 Sesto Fiorentino, Italy
- Istituto Nazionale di Ottica del Consiglio Nazionale delle Ricerche (CNR-INO), 50019 Sesto Fiorentino, Italy
| | - M Zaccanti
- European Laboratory for Nonlinear Spectroscopy (LENS), 50019 Sesto Fiorentino, Italy
- Istituto Nazionale di Ottica del Consiglio Nazionale delle Ricerche (CNR-INO), 50019 Sesto Fiorentino, Italy
| | - G Roati
- European Laboratory for Nonlinear Spectroscopy (LENS), 50019 Sesto Fiorentino, Italy
- Istituto Nazionale di Ottica del Consiglio Nazionale delle Ricerche (CNR-INO), 50019 Sesto Fiorentino, Italy
| | - F Scazza
- European Laboratory for Nonlinear Spectroscopy (LENS), 50019 Sesto Fiorentino, Italy
- Istituto Nazionale di Ottica del Consiglio Nazionale delle Ricerche (CNR-INO), 50019 Sesto Fiorentino, Italy
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Impact of the transverse direction on the many-body tunneling dynamics in a two-dimensional bosonic Josephson junction. Sci Rep 2020; 10:21476. [PMID: 33293575 PMCID: PMC7722723 DOI: 10.1038/s41598-020-78173-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2020] [Accepted: 10/29/2020] [Indexed: 11/08/2022] Open
Abstract
Tunneling in a many-body system appears as one of the novel implications of quantum physics, in which particles move in space under an otherwise classically-forbidden potential barrier. Here, we theoretically describe the quantum dynamics of the tunneling phenomenon of a few intricate bosonic clouds in a closed system of a two-dimensional symmetric double-well potential. We examine how the inclusion of the transverse direction, orthogonal to the junction of the double-well, can intervene in the tunneling dynamics of bosonic clouds. We use a well-known many-body numerical method, called the multiconfigurational time-dependent Hartree for bosons (MCTDHB) method. MCTDHB allows one to obtain accurately the time-dependent many-particle wavefunction of the bosons which in principle entails all the information of interest about the system under investigation. We analyze the tunneling dynamics by preparing the initial state of the bosonic clouds in the left well of the double-well either as the ground, longitudinally or transversely excited, or a vortex state. We unravel the detailed mechanism of the tunneling process by analyzing the evolution in time of the survival probability, depletion and fragmentation, and the many-particle position, momentum, and angular-momentum expectation values and their variances. As a general rule, all objects lose coherence while tunneling through the barrier and the states which include transverse excitations do so faster. In particular for the later states, we show that even when the transverse direction is seemingly frozen, prominent many-body dynamics in a two-dimensional bosonic Josephson junction occurs. Implications are briefly discussed.
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Villois A, Proment D, Krstulovic G. Irreversible Dynamics of Vortex Reconnections in Quantum Fluids. PHYSICAL REVIEW LETTERS 2020; 125:164501. [PMID: 33124852 DOI: 10.1103/physrevlett.125.164501] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Revised: 06/30/2020] [Accepted: 09/10/2020] [Indexed: 06/11/2023]
Abstract
We statistically study vortex reconnections in quantum fluids by evolving different realizations of vortex Hopf links using the Gross-Pitaevskii model. Despite the time reversibility of the model, we report clear evidence that the dynamics of the reconnection process is time irreversible, as reconnecting vortices tend to separate faster than they approach. Thanks to a matching theory devised concurrently by Proment and Krstulovic [Phys. Rev. Fluids 5, 104701 (2020)PLFHBR2469-990X10.1103/PhysRevFluids.5.104701], we quantitatively relate the origin of this asymmetry to the generation of a sound pulse after the reconnection event. Our results have the prospect of being tested in several quantum fluid experiments and, theoretically, may shed new light on the energy transfer mechanisms in both classical and quantum turbulent fluids.
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Affiliation(s)
- Alberto Villois
- Department of Physics, University of Bath, Bath BA2 7AY, United Kingdom and School of Mathematics, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, United Kingdom
| | - Davide Proment
- School of Mathematics, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, United Kingdom
| | - Giorgio Krstulovic
- Université Côte d'Azur, Observatoire de la Côte d'Azur, CNRS, Laboratoire Lagrange, Bd de l'Observatoire, CS 34229, 06304 Nice cedex 4, France
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Kwon WJ, Del Pace G, Panza R, Inguscio M, Zwerger W, Zaccanti M, Scazza F, Roati G. Strongly correlated superfluid order parameters from dc Josephson supercurrents. Science 2020; 369:84-88. [DOI: 10.1126/science.aaz2463] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2019] [Accepted: 04/27/2020] [Indexed: 11/02/2022]
Affiliation(s)
- W. J. Kwon
- Istituto Nazionale di Ottica del Consiglio Nazionale delle Ricerche (CNR-INO), 50019 Sesto Fiorentino, Italy
- European Laboratory for Nonlinear Spectroscopy (LENS), 50019 Sesto Fiorentino, Italy
| | - G. Del Pace
- European Laboratory for Nonlinear Spectroscopy (LENS), 50019 Sesto Fiorentino, Italy
- Department of Physics and Astronomy, University of Florence, 50019 Sesto Fiorentino, Italy
| | - R. Panza
- Istituto Nazionale di Ottica del Consiglio Nazionale delle Ricerche (CNR-INO), 50019 Sesto Fiorentino, Italy
- European Laboratory for Nonlinear Spectroscopy (LENS), 50019 Sesto Fiorentino, Italy
| | - M. Inguscio
- Istituto Nazionale di Ottica del Consiglio Nazionale delle Ricerche (CNR-INO), 50019 Sesto Fiorentino, Italy
- European Laboratory for Nonlinear Spectroscopy (LENS), 50019 Sesto Fiorentino, Italy
- Department of Engineering, Campus Bio-Medico University of Rome, 00128 Rome, Italy
| | - W. Zwerger
- Physics Department, Technische Universität München, 85747 Garching, Germany
| | - M. Zaccanti
- Istituto Nazionale di Ottica del Consiglio Nazionale delle Ricerche (CNR-INO), 50019 Sesto Fiorentino, Italy
- European Laboratory for Nonlinear Spectroscopy (LENS), 50019 Sesto Fiorentino, Italy
| | - F. Scazza
- Istituto Nazionale di Ottica del Consiglio Nazionale delle Ricerche (CNR-INO), 50019 Sesto Fiorentino, Italy
- European Laboratory for Nonlinear Spectroscopy (LENS), 50019 Sesto Fiorentino, Italy
| | - G. Roati
- Istituto Nazionale di Ottica del Consiglio Nazionale delle Ricerche (CNR-INO), 50019 Sesto Fiorentino, Italy
- European Laboratory for Nonlinear Spectroscopy (LENS), 50019 Sesto Fiorentino, Italy
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