scholarly journals Cavity assisted measurements of heat and work in optical lattices

Quantum ◽  
2018 ◽  
Vol 2 ◽  
pp. 42 ◽  
Author(s):  
Louis Villa ◽  
Gabriele De Chiara
Keyword(s):  
Ultracold Atoms ◽  
Optical Lattices ◽  
Photon Number ◽  
Strongly Correlated ◽  
Body System ◽  
Many Body ◽  
Optical Cavities ◽  
One Dimensional ◽  
Interaction Terms ◽  
The One

We propose a method to experimentally measure the internal energy of a system of ultracold atoms trapped in optical lattices by coupling them to the fields of two optical cavities. We show that the tunnelling and self-interaction terms of the one-dimensional Bose-Hubbard Hamiltonian can be mapped to the field and photon number of each cavity, respectively. We compare the energy estimated using this method with numerical results obtained using the density matrix renormalisation group algorithm. Our method can be employed for the assessment of power and efficiency of thermal machines whose working substance is a strongly correlated many-body system.

Variational Many Body States for the U=∞ Hubbard Model

1991 ◽  
Vol 05 (10) ◽  
pp. 1791-1800 ◽  
Author(s):  
C. Stephen Hellberg ◽  
E. J. Mele
Keyword(s):  
Hubbard Model ◽  
General Class ◽  
Exact Results ◽  
Strongly Correlated ◽  
Many Body ◽  
Local Constraints ◽  
Double Occupancy ◽  
One Dimensional ◽  
Lattice Fermions ◽  
The One

We study a general class of variational wavefunctions for strongly correlated lattice fermions. The wavefunctions considered here automatically satisfy local constraints of no double occupancy and include correlations between opposite spin particles in a very physical way. We calculate the energy and correlation functions for the one dimensional U=∞ Hubbard model, where a comparison with exact results is made. We briefly report on preliminary results for the t-J model.

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 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 Strong-coupling ansatz for the one-dimensional Fermi gas in a harmonic potential

2015 ◽  
Vol 1 (6) ◽  
pp. e1500197 ◽  
Author(s):  
Jesper Levinsen ◽  
Pietro Massignan ◽  
Georg M. Bruun ◽  
Meera M. Parish
Keyword(s):  
Fermi Gas ◽  
Harmonic Potential ◽  
Chain Model ◽  
Many Body ◽  
Exact Methods ◽  
One Dimensional ◽  
Heisenberg Spin Chain ◽  
Precise Knowledge ◽  
Short Range Repulsion ◽  
The One

A major challenge in modern physics is to accurately describe strongly interacting quantum many-body systems. One-dimensional systems provide fundamental insights because they are often amenable to exact methods. However, no exact solution is known for the experimentally relevant case of external confinement. We propose a powerful ansatz for the one-dimensional Fermi gas in a harmonic potential near the limit of infinite short-range repulsion. For the case of a single impurity in a Fermi sea, we show that our ansatz is indistinguishable from numerically exact results in both the few- and many-body limits. We furthermore derive an effective Heisenberg spin-chain model corresponding to our ansatz, valid for any spin-mixture, within which we obtain the impurity eigenstates analytically. In particular, the classical Pascal’s triangle emerges in the expression for the ground-state wave function. As well as providing an important benchmark for strongly correlated physics, our results are relevant for emerging quantum technologies, where a precise knowledge of one-dimensional quantum states is paramount.

MOLECULAR DYNAMICS APPROACH TO CORRELATION CLUSTERING

2008 ◽  
Vol 19 (09) ◽  
pp. 1349-1358 ◽  
Author(s):  
R. SUMI ◽  
Z. NÉDA
Keyword(s):  
Phase Transition ◽  
Molecular Dynamics ◽  
Mechanical Equilibrium ◽  
Body System ◽  
Many Body ◽  
Competing Interactions ◽  
Correlation Clustering ◽  
Simulated System ◽  
The One ◽  
Dynamics Simulations

A many-body system with co-existing attractive and repulsive interactions is considered on a ring. The competing interactions lead to a frustration similar with the one existing in Correlation Clustering (CC). The optimal mechanical equilibrium of the system is searched by molecular dynamics simulations. As a function of the disorder quenched in the interactions, the system exhibits the phase-transition recently reported in CC. The simulated system can be considered as a continuous and efficient approach to the otherwise discrete, NP hard CC problem.

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