scholarly journals Quantum many-body adiabaticity, topological Thouless pump and driven impurity in a one-dimensional quantum fluid

2018 ◽  
Author(s):  
Oleg Lychkovskiy ◽  
Oleksandr Gamayun ◽  
Vadim Cheianov
Keyword(s):  
Many Body ◽  
One Dimensional ◽  
Quantum Fluid

scholarly journals Undecidability in quantum thermalization

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Naoto Shiraishi ◽  
Keiji Matsumoto
Keyword(s):  
Turing Machine ◽  
Thermal Equilibrium ◽  
General Theorem ◽  
Nearest Neighbour ◽  
Many Body ◽  
Initial State ◽  
One Dimensional ◽  
Universal Turing Machine ◽  
Many Body Systems ◽  
Neighbour Interaction

AbstractThe investigation of thermalization in isolated quantum many-body systems has a long history, dating back to the time of developing statistical mechanics. Most quantum many-body systems in nature are considered to thermalize, while some never achieve thermal equilibrium. The central problem is to clarify whether a given system thermalizes, which has been addressed previously, but not resolved. Here, we show that this problem is undecidable. The resulting undecidability even applies when the system is restricted to one-dimensional shift-invariant systems with nearest-neighbour interaction, and the initial state is a fixed product state. We construct a family of Hamiltonians encoding dynamics of a reversible universal Turing machine, where the fate of a relaxation process changes considerably depending on whether the Turing machine halts. Our result indicates that there is no general theorem, algorithm, or systematic procedure determining the presence or absence of thermalization in any given Hamiltonian.

scholarly journals Probing the edge between integrability and quantum chaos in interacting few-atom systems

Quantum ◽  
2021 ◽  
Vol 5 ◽  
pp. 486
Author(s):  
Thomás Fogarty ◽  
Miguel Ángel García-March ◽  
Lea F. Santos ◽  
Nathan L. Harshman
Keyword(s):  
Quantum Chaos ◽  
Cold Atoms ◽  
Quantum Systems ◽  
Particle Interactions ◽  
Body System ◽  
Many Body ◽  
One Dimensional ◽  
The Core ◽  
Emergence Of Chaos ◽  
Number Of Particles

Interacting quantum systems in the chaotic domain are at the core of various ongoing studies of many-body physics, ranging from the scrambling of quantum information to the onset of thermalization. We propose a minimum model for chaos that can be experimentally realized with cold atoms trapped in one-dimensional multi-well potentials. We explore the emergence of chaos as the number of particles is increased, starting with as few as two, and as the number of wells is increased, ranging from a double well to a multi-well Kronig-Penney-like system. In this way, we illuminate the narrow boundary between integrability and chaos in a highly tunable few-body system. We show that the competition between the particle interactions and the periodic structure of the confining potential reveals subtle indications of quantum chaos for 3 particles, while for 4 particles stronger signatures are seen. The analysis is performed for bosonic particles and could also be extended to distinguishable fermions.

scholarly journals Do we need a non-perturbative theory of Bose-Einstein condensation?

2021 ◽  
Vol 2103 (1) ◽  
pp. 012200
Author(s):  
K G Zloshchastiev
Keyword(s):  
Phase Contrast ◽  
Einstein Condensate ◽  
Einstein Condensation ◽  
One Dimensional ◽  
Quantum Fluid ◽  
Bose Einstein Condensate ◽  
Dipole Force ◽  
Theoretical Assumptions ◽  
Bose Einstein ◽  
Best Fit

Abstract We recall the experimental data of one-dimensional axial propagation of sound near the center of the Bose-Einstein condensate cloud, which used the optical dipole force method of a focused laser beam and rapid sequencing of nondestructive phase-contrast images. We reanalyze these data within the general quantum fluid framework but without model-specific theoretical assumptions; using the standard best fit techniques. We demonstrate that some of their features cannot be explained by means of the perturbative two-body approximation and Gross-Pitaevskii model, and conjecture possible solutions.

scholarly journals Probing non-thermal density fluctuations in the one-dimensional Bose gas

2017 ◽  
Vol 3 (3) ◽  
Author(s):  
Jacopo De Nardis ◽  
Milosz Panfil ◽  
Andrea Gambassi ◽  
Leticia Cugliandolo ◽  
Robert Konik ◽  
...  
Keyword(s):  
Spatial Dimension ◽  
Bose Gas ◽  
Density Fluctuations ◽  
Dynamical Structure ◽  
Many Body ◽  
Initial State ◽  
One Dimensional ◽  
Fluctuation Dissipation ◽  
Quantum Integrable Models ◽  
The One

Quantum integrable models display a rich variety of non-thermal excited states with unusual properties. The most common way to probe them is by performing a quantum quench, i.e., by letting a many-body initial state unitarily evolve with an integrable Hamiltonian. At late times these systems are locally described by a generalized Gibbs ensemble with as many effective temperatures as their local conserved quantities. The experimental measurement of this macroscopic number of temperatures remains elusive. Here we show that they can be obtained for the Bose gas in one spatial dimension by probing the dynamical structure factor of the system after the quench and by employing a generalized fluctuation-dissipation theorem that we provide. Our procedure allows us to completely reconstruct the stationary state of a quantum integrable system from state-of-the-art experimental observations.

scholarly journals A many-body dissipative particle dynamics with energy conservation study of droplets icing on microstructure surfaces

2021 ◽  
Vol 3 (1) ◽  
Author(s):  
Chenyang Wang ◽  
Xiao Wu ◽  
Pengfei Hao ◽  
Feng He ◽  
Xiwen Zhang
Keyword(s):  
Contact Angle ◽  
Dissipative Particle Dynamics ◽  
Real Life ◽  
Transfer Model ◽  
Change Model ◽  
Droplet Volume ◽  
Many Body ◽  
Cold Surface ◽  
One Dimensional ◽  
Large Factor

AbstractDroplets icing has important applications in real life. The icing process of droplets on microstructure is explored based on the MDPDE method in this study. Firstly, the correctness of the heat transfer model was verified by one-dimensional heat conduction simulation, and then the feasibility of the phase change model was verified by investigating the icing process of droplets. The influence of cold surface temperature, droplet volume and contact angle on freezing time of droplets was discussed, and it was found that the temperature of cold surfaces had a greater effect on freezing. We finally explored the influence of different microstructure surfaces on the icing of droplets, and results showed that the presence of microstructures greatly enhanced the anti-icing effect of the surface. In our research, the contact angle is a relatively large factor affecting the icing of droplets. In addition, it was discovered that the droplet had the strongest ability to delay freezing on the surface of triangle microstructures with a contact angle of 157.1°.

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