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The combination of non-Hermitian physics and strong correlations can give rise to new effects in open quantum many-body systems with balanced gain and loss. We propose a generalized Anderson impurity model that includes non-Hermitian…

Strongly Correlated Electrons · Physics 2018-08-23 Jose A. S. Lourenco , Ronivon L. Eneias , Rodrigo G. Pereira

Topological phases are greatly enriched by including non-Hermiticity. While most works focus on the topology of the eigenvalues and eigenstates, how topologically nontrivial non-Hermitian systems behave in dynamics has only drawn limited…

Mesoscale and Nanoscale Physics · Physics 2023-08-16 Tian-Rui Liu , Kai Bai , Jia-Zheng Li , Liang Fang , Duanduan Wan , Meng Xiao

It is possible to simulate the dynamics of a single spin-$1/2$ ($\mathsf{PT~}$ symmetric) system by conveniently embedding it into a subspace of a larger Hilbert space with unitary dynamics. Our goal is to formulate a many body…

Quantum Physics · Physics 2021-08-04 Anant V. Varma , Sourin Das

Supplementing the Heisenberg model with a Hubbard-commuting kinetic of electrons adds to its spectrum without interference. One consequence is the precise incorporation of canonical linear spin wave theory within the time-dependent…

Strongly Correlated Electrons · Physics 2024-12-11 Rohit Hegde

A non-Hermitian shortcut to adiabaticity is introduced. By adding an imaginary term in the diagonal elements of the Hamiltonian of a two state quantum system, we show how one can cancel the nonadiabatic losses and perform an arbitrarily…

Quantum Physics · Physics 2013-06-05 Boyan T. Torosov , Giuseppe Della Valle , Stefano Longhi

A new diagrammatic technique is developed to describe nonlocal effects (e.g., pseudogap formation) in the Hubbard-like models. In contrast to cluster approaches, this method utilizes an exact transition to the dual set of variables, and it…

Strongly Correlated Electrons · Physics 2007-05-23 A. N. Rubtsov , M. I. Katsnelson , A. I. Lichtenstein

We propose a mechanism for solving the `negative sign problem'---the inability to assign non-negative weights to quantum Monte Carlo configurations---for a toy model consisting of a frustrated triplet of spin-$1/2$ particles interacting…

Statistical Mechanics · Physics 2019-04-03 Itay Hen

A fundamental open issue in physics is whether and how the fermion sign problem in quantum Monte Carlo (QMC) simulations can be solved generically. Here, we show that Majorana-time-reversal (MTR) symmetries can provide a unifying principle…

Strongly Correlated Electrons · Physics 2016-12-26 Zi-Xiang Li , Yi-Fan Jiang , Hong Yao

We study a non-Hermitian generalization of strongly correlated quantum systems in which the transfer energy of electrons is asymmetric. It is known that a non-Hermitian critical point is equal to the inverse localization length of a…

Strongly Correlated Electrons · Physics 2007-05-23 Yuichi Nakamura , Naomichi Hatano

We propose a hybrid quantum-classical method to investigate the equilibrium physics and the dynamics of strongly correlated fermionic models with spin-based quantum processors. Our proposal avoids the usual pitfalls of fermion-to-spin…

Quantum Physics · Physics 2024-06-21 Antoine Michel , Loïc Henriet , Christophe Domain , Antoine Browaeys , Thomas Ayral

A recently introduced class of quantum spherical spin models is considered in detail. Since the spherical constraint already contains a kinetic part, the Hamiltonian need not have kinetic term. As a consequence, situations with or without…

Condensed Matter · Physics 2009-11-10 R. Serral Gracia , Th. M. Nieuwenhuizen

A class of pseudo-hermitian quantum system with an explicit form of the positive-definite metric in the Hilbert space is presented. The general method involves a realization of the basic canonical commutation relations defining the quantum…

Quantum Physics · Physics 2010-03-15 Pijush K. Ghosh

Quantum phase transitions are usually studied in terms of Hermitian Hamiltonians. However, cold-atom experiments are intrinsically non-Hermitian due to spontaneous decay. Here, we show that non-Hermitian systems exhibit quantum phase…

Quantum Gases · Physics 2014-10-08 Tony E. Lee , Ching-Kit Chan

We introduce two dimensional fermionic band models with two orbitals per lattice site, or one spinful orbital, and which have a non-zero topological Chern number that can be changed by varying the ratio of hopping parameters. A…

Strongly Correlated Electrons · Physics 2013-02-14 Miguel A. N. Araújo , Eduardo V. Castro , Pedro D. Sacramento

The notorious sign problem severely limits the applicability of quantum Monte Carlo (QMC) simulations, as statistical errors grow exponentially with system size and inverse temperature. A recent proposal of a quantum-computing stochastic…

Quantum Physics · Physics 2026-03-11 Kwai-Kong Ng , Min-Fong Yang

Quantum systems with a non-conserved probability can be described by means of non-Hermitian Hamiltonians and non-unitary dynamics. In this paper, the case in which the degrees of freedom can be partitioned in two subsets with light and…

Quantum Physics · Physics 2016-10-21 Alessandro Sergi

Using numerically exact diagonalization, we study the correlated Haldane-Hubbard model in the presence of dissipation. Such dissipation can be modeled at short times by the dynamics governed by an effective non-Hermitian Hamiltonian, of…

Strongly Correlated Electrons · Physics 2023-08-29 Can Wang , Tian-Cheng Yi , Jian Li , Rubem Mondaini

By the spin-fermion formula, the Hubbard model on the honeycomb lattice is represented by a U(2) gauge theory in the mean field method, non-Abelian vortex solutions are constructed based on this theory. The quantization condition shows that…

Superconductivity · Physics 2015-06-04 Qiu-Hong Huo , Yunguo Jiang , Ru-Zhi Wang , Hui Yan

Simulating models for quantum correlated matter unveils the inherent limitations of deterministic classical computations. In particular, in the case of quantum Monte Carlo methods, this is manifested by the emergence of negative weight…

Strongly Correlated Electrons · Physics 2022-11-23 Tian-Cheng Yi , Richard T. Scalettar , Rubem Mondaini

We study a non-Hermitian generalization of quantum systems in which an imaginary vector potential is added to the momentum operator. In the tight-binding approximation, we make the hopping energy asymmetric in the Hermitian Hamiltonian. In…

Strongly Correlated Electrons · Physics 2007-05-23 Yuichi Nakamura , Naomichi Hatano