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We exactly solve a quantum Fermi accelerator model consisting of a time-independent non-Hermitian Hamiltonian with time-dependent Dirichlet boundary conditions. A Hilbert space for such systems can be defined in two equivalent ways, either…

Quantum Physics · Physics 2024-03-20 Andreas Fring , Takano Taira

Quantum mechanics features a variety of distinct properties such as coherence and entanglement, which could be explored to showcase potential advantages over classical counterparts in information processing. In general, legitimate quantum…

Quantum Physics · Physics 2023-08-17 Fuchuan Wei , Zhenhuan Liu , Guoding Liu , Zizhao Han , Xiongfeng Ma , Dong-Ling Deng , Zhengwei Liu

Modeling non-Hermitian Hamiltonians is increasingly important in classical and quantum domains, especially when studying open systems, $PT$ symmetry, and resonances. However, the quantum simulation of these models has been limited by the…

Quantum Physics · Physics 2025-02-20 Anastashia Jebraeilli , Michael R. Geller

We introduce a quantum algorithm to efficiently prepare states with a small energy variance at the target energy. We achieve it by filtering a product state at the given energy with a Lorentzian filter of width $\delta$. Given a local…

Quantum Physics · Physics 2024-07-03 Reinis Irmejs , Mari Carmen Bañuls , J. Ignacio Cirac

An algorithm for finding the bound-state eigenvalues and eigenfunctions of a Hermitian Hamiltonian operator using Green's method, developed by Waxman\cite{W98},has been extended to include non-Hermitian Hamiltonian operators.

Quantum Physics · Physics 2017-10-25 S. R. Chamberlain , J. G. Tucker , J. M. Conroy , H. G. Miller

We investigate the dynamics of a quantum system coupled linearly to Gaussian white noise using functional methods. By performing the integration over the noisy field in the evolution operator, we get an equivalent non-Hermitian Hamiltonian,…

Quantum Physics · Physics 2016-07-20 O. Oliveira , W. de Paula , T. Frederico , M. S. Hussein

Hybrid machine learning based on Hamiltonian formulations has recently been successfully demonstrated for simple mechanical systems, both energy conserving and not energy conserving. We introduce a pseudo-Hamiltonian formulation that is a…

Machine Learning · Computer Science 2023-02-15 Sølve Eidnes , Alexander J. Stasik , Camilla Sterud , Eivind Bøhn , Signe Riemer-Sørensen

We discuss the dynamical quantum systems which turn out to be bi-unitary with respect to the same alternative Hermitian structures in a infinite-dimensional complex Hilbert space. We give a necessary and sufficient condition so that the…

Mathematical Physics · Physics 2007-05-23 G. Marmo , G. Scolarici , A. Simoni , F. Ventriglia

We devise a generic and experimentally accessible recipe to prepare boundary states of topological or nontopological quantum systems through an interplay between coherent Hamiltonian dynamics and local dissipation. Intuitively, our recipe…

Mesoscale and Nanoscale Physics · Physics 2023-12-13 Fan Yang , Paolo Molignini , Emil J. Bergholtz

We investigate the computational power of creating steady-states of quantum dissipative systems whose evolution is governed by time-independent and local couplings to a memoryless environment. We show that such a model allows for efficient…

Quantum Physics · Physics 2009-09-24 Frank Verstraete , Michael M. Wolf , J. Ignacio Cirac

Chaotic behavior or lack thereof in non-Hermitian systems is often diagnosed via spectral analysis of associated complex eigenvalues. Very recently, singular values of the associated non-Hermitian systems have been proposed as an effective…

Statistical Mechanics · Physics 2025-03-18 Mahaveer Prasad , S. Harshini Tekur , Bijay Kumar Agarwalla , Manas Kulkarni

Any quantum system with a non-trivial Hamiltonian is able to simulate any other Hamiltonian evolution provided that a sufficiently large group of unitary control operations is available. We show that there exist finite groups with this…

Quantum Physics · Physics 2023-11-27 Pawel Wocjan , Martin Roetteler , Dominik Janzing , Thomas Beth

Non-Hermitian systems with specific forms of Hamiltonians can exhibit novel phenomena. However, it is difficult to study their quantum thermodynamical properties. In particular, the calculation of work statistics can be challenging in…

Quantum Physics · Physics 2021-09-13 Zheng-Yang Zhou , Ze-Liang Xiang J. Q. You , Franco Nori

We show that several Hamiltonians that are $\mathcal{PT}$ symmetric may be taken to Hermitian Hamiltonians via a non-unitary transformation and vice versa. We also show that for some specific Hamiltonians such non-unitary transformations…

The ordinary time-dependent perturbation theory of quantum mechanics, that describes the interaction of a stationary system with a time-dependent perturbation, predicts that the transition probabilities induced by the perturbation are…

Quantum Physics · Physics 2017-10-11 S. Longhi , G. Della Valle

While dissipation has traditionally been viewed as an obstacle to quantum coherence, it is increasingly recognized as a powerful computational resource. Dissipative protocols can prepare complex many-body quantum states by leveraging…

Quantum Physics · Physics 2025-10-02 Lin Lin

We develop a general optimization strategy for performing a chosen unitary or non-unitary task on an open quantum system. The goal is to design a controlled time-dependent system Hamiltonian by variationally minimizing or maximizing a…

Quantum Physics · Physics 2016-03-29 Jens Clausen , Guy Bensky , Gershon Kurizki

We show that quantum nondemolition (QND) measurements can be used to realize measurement-based imaginary time evolution. In our proposed scheme, repeated weak QND measurements are used to estimate the energy of a given Hamiltonian. Based on…

We show that the standard techniques that are utilized to study the classical like properties of the pure states for Hermitian systems can be adjusted to investigate the classicality of pure states for non-Hermitian systems. The method is…

Quantum Physics · Physics 2020-01-13 K Zelaya , S. Dey , V. Hussin , O. Rosas-Ortiz

The evolution of a closed quantum system is described by a unitary operator generated by a Hermitian Hamiltonian. However, when certain degrees of freedom are coupled to an environment, the relevant dynamics can be captured by non-unitary…