Probing the superfluid-insulator phase transition by a non-Hermitian external field

• URL: http://arxiv.org/abs/2106.15040v1
• Date: Tue, 29 Jun 2021 00:47:40 GMT
• Title: Probing the superfluid-insulator phase transition by a non-Hermitian external field
• Authors: X. Z. Zhang, and Z. Song
• Abstract summary: We study the response of a thermal state of the Hubbard-like system to either global or local non-Hermitian perturbations. We show that the dynamical response of the system is strongly sensitive to the underlying quantum phase transition (QPT) from a Mott insulator to a superfluid state.
• Score: 0.0
• License: http://creativecommons.org/licenses/by/4.0/
• Abstract: We study the response of a thermal state of the Hubbard-like system to either global or local non-Hermitian perturbation, which coalesces the degenerate ground state within the $U(1)$ symmetry breaking phase. We show that the dynamical response of the system is strongly sensitive to the underlying quantum phase transition (QPT) from a Mott insulator to a superfluid state. The Uhlmann fidelity in the superfluid phase decays to a steady value determined by the order of the exceptional point (EP) within the subspace spanned by the degenerate ground states but remains almost unchanged in the Mott insulating phase. It demonstrates that the phase diagram at zero temperature is preserved even though a local probing field is applied. Specifically, two celebrated models including the Bose-Hubbard model and the Jaynes-Cummings-Hubbard model are employed to demonstrate this property in the finite-size system, wherein fluctuations of the boson and polariton number are observed based on EP dynamics. This work presents an alternative approach to probe the superfluid-insulator QPT at non-zero temperature.

Related papers

• An unusual phase transition in a non-Hermitian Su-Schrieffer-Heeger model [0.0]
  This article studies a non-Hermitian Su-Schrieffer-Heeger (SSH) model which has periodically staggered Hermitian and non-Hermitian dimers. We find that the system supports only complex eigenspectra for all values of $u neq 0$ and it stabilizes only non-trivial insulating phase for higher loss-gain strength.
  arXiv  Detail & Related papers  (2024-11-21T17:21:48Z)
• Hidden exceptional point, localization-delocalization phase transition in Hermitian bosonic Kitaev model [0.0]
  A Hermitian bosonic Kitaev model supports a non-Hermitian core matrix with exceptional points (EPs) We show the connection between the hidden EP and the localization-delocalization transition in the equivalent systems. Numerical simulations of the time evolution reveal a clear transition point at the EP.
  arXiv  Detail & Related papers  (2024-10-21T12:52:18Z)
• Entanglement phase transition due to reciprocity breaking without measurement or post-selection [59.63862802533879]
  EPT occurs for a system undergoing purely unitary evolution. We analytically derive the entanglement entropy out of and at the critical point for the $l=1$ and $l/N ll 1$ case.
  arXiv  Detail & Related papers  (2023-08-28T14:28:59Z)
• Photoinduced prethermal order parameter dynamics in the two-dimensional large-$N$ Hubbard-Heisenberg model [77.34726150561087]
  We study the microscopic dynamics of competing ordered phases in a two-dimensional correlated electron model. We simulate the light-induced transition between two competing phases.
  arXiv  Detail & Related papers  (2022-05-13T13:13:31Z)
• Quantum critical behavior of entanglement in lattice bosons with cavity-mediated long-range interactions [0.0]
  We analyze the ground-state entanglement entropy of the extended Bose-Hubbard model with infinite-range interactions. This model describes the low-energy dynamics of ultracold bosons tightly bound to an optical lattice and dispersively coupled to a cavity mode.
  arXiv  Detail & Related papers  (2022-04-16T04:10:57Z)
• Accessing the topological Mott insulator in cold atom quantum simulators with realistic Rydberg dressing [58.720142291102135]
  We investigate a realistic scenario for the quantum simulation of such systems using cold Rydberg-dressed atoms in optical lattices. We perform a detailed analysis of the phase diagram at half- and incommensurate fillings, in the mean-field approximation. We furthermore study the stability of the phases with respect to temperature within the mean-field approximation.
  arXiv  Detail & Related papers  (2022-03-28T14:55:28Z)
• Uhlmann Fidelity and Fidelity Susceptibility for Integrable Spin Chains at Finite Temperature: Exact Results [68.8204255655161]
  We show that the proper inclusion of the odd parity subspace leads to the enhancement of maximal fidelity susceptibility in the intermediate range of temperatures. The correct low-temperature behavior is captured by an approximation involving the two lowest many-body energy eigenstates.
  arXiv  Detail & Related papers  (2021-05-11T14:08:02Z)
• Impurity dephasing in a Bose-Hubbard model [0.0]
  We study the dynamics of a two-level impurity embedded in a two-dimensional Bose-Hubbard model at zero temperature. Results for the decoherence across the whole phase diagram are presented, with a focus on the critical region close to the transition between superfluid and Mott insulator.
  arXiv  Detail & Related papers  (2020-11-27T14:44:13Z)
• Quantum Phase Transition in a Quantum Ising Chain at Nonzero Temperatures [0.0]
  We study the response of a thermal state of an Ising chain to a nonlocal non-Hermitian perturbation. The dynamic responses for initial thermal states in different quantum phases are distinct.
  arXiv  Detail & Related papers  (2020-09-24T07:41:32Z)
• Analog cosmological reheating in an ultracold Bose gas [58.720142291102135]
  We quantum-simulate the reheating-like dynamics of a generic cosmological single-field model in an ultracold Bose gas. Expanding spacetime as well as the background oscillating inflaton field are mimicked in the non-relativistic limit. The proposed experiment has the potential of exploring the evolution up to late times even beyond the weak coupling regime.
  arXiv  Detail & Related papers  (2020-08-05T18:00:26Z)
• Probing eigenstate thermalization in quantum simulators via fluctuation-dissipation relations [77.34726150561087]
  The eigenstate thermalization hypothesis (ETH) offers a universal mechanism for the approach to equilibrium of closed quantum many-body systems. Here, we propose a theory-independent route to probe the full ETH in quantum simulators by observing the emergence of fluctuation-dissipation relations. Our work presents a theory-independent way to characterize thermalization in quantum simulators and paves the way to quantum simulate condensed matter pump-probe experiments.
  arXiv  Detail & Related papers  (2020-07-20T18:00:02Z)

This list is automatically generated from the titles and abstracts of the papers in this site.

This site does not guarantee the quality of this site (including all information) and is not responsible for any consequences.