English
Related papers

Related papers: Models with non-Hermitian Hamiltonian and optical …

200 papers

We present an evaluation of some recent attempts at understanding the role of pseudo-Hermitian and PT-symmetric Hamiltonians in modeling unitary quantum systems and elaborate on a particular physical phenomenon whose discovery originated in…

Quantum Physics · Physics 2015-05-14 Ali Mostafazadeh

Non-Hermitian dynamics in quantum systems preserves the rank of the state density operator. Using this insight, we develop a geometric framework to describe its time evolution. In particular, we identify mutually orthogonal coherent and…

Quantum Physics · Physics 2025-05-06 Niklas Hörnedal , Oskar A. Prośniak , Adolfo del Campo , Aurélia Chenu

We show that there is a double counting in the standard model of $n\bar{n}$ mixing in the medium, resulting in full cancellation of leading terms. The direct calculation of $n\bar{n}$ transition, annihilation is performed. For lower limit…

High Energy Physics - Phenomenology · Physics 2007-05-23 V. I. Nazaruk

Non-linear effects and non-Hermitian phenomena unveil additional intricate facets in topological matter physics. They can naturally intertwine to enable advanced functionalities in topoelectrical circuits and photonic structures. Here, we…

Optics · Physics 2024-06-27 Vlad Simonian , Daria A. Smirnova , Maxim A. Gorlach

Here we present an strategy for the derivation of a time-dependent Dyson map which ensures simultaneously the unitarity of the time evolution and the observability of a quasi-Hermitian Hamiltonian. The time-dependent Dyson map is derived…

Quantum Physics · Physics 2016-11-28 F. S. Luiz , M. A. Pontes , M. H. Y. Moussa

Non-Hermitian quantum systems exhibit fascinating characteristics such as non-Hermitian topological phenomena and skin effect, yet their studies are limited by the intrinsic difficulties associated with their eigenvalue problems, especially…

Mesoscale and Nanoscale Physics · Physics 2024-01-23 Guang Yang , Yongkang Li , Yongxu Fu , Zhenduo Wang , Yi Zhang

In a previous paper (arXiv:math-ph/0604055) we introduced a very simple PT-symmetric non-Hermitian Hamiltonian with real spectrum and derived a closed formula for the metric operator relating the problem to a Hermitian one. In this note we…

Mathematical Physics · Physics 2009-11-13 David Krejcirik

In polaritons, the properties of matter are modified by mixing the molecular transitions with light modes inside a cavity. Resultant hybrid light-matter states exhibit energy level shifts, are delocalized over many molecular units and have…

We demonstrate that quantum fluctuations can cause, under certain conditions, the dynamical instability of pure states that can result in their evolution into mixed states. It is shown that the degree and type of such an instability are…

Quantum Physics · Physics 2015-11-19 Konstantin G. Zloshchastiev

Hamiltonian simulation is one of the most promising applications of quantum computers, and the product formula is one of the most important methods for this purpose. Previous related work has mainly focused on the worst$-$case or…

Quantum Physics · Physics 2024-09-04 Langyu Li

Recently, apparent nonphysical implications of non-Hermitian quantum mechanics (NHQM) have been discussed in the literature. In particular, the apparent violation of the no-signaling theorem, discrimination of nonorthogonal states, and the…

Quantum Physics · Physics 2019-12-25 Chia-Yi Ju , Adam Miranowicz , Guang-Yin Chen , Franco Nori

We represent low dimensional quantum mechanical Hamiltonians by moderately sized finite matrices that reproduce the lowest O(10) boundstate energies and wave functions to machine precision. The method extends also to Hamiltonians that are…

Quantum Physics · Physics 2015-06-03 Johann Foerster , Alejandro Saenz , Ulli Wolff

The non-Hermitian paradigm of quantum systems displays salient features drastically different from Hermitian counterparts. In this work, we focus on one such aspect, the difference of evolving quantum ensembles under $H_{\mathrm{nh}}$…

Quantum Physics · Physics 2025-10-03 Soumik Bandyopadhyay , Philipp Hauke , Sudipto Singha Roy

The corrections to the model of $n\bar{n}$ transitions in the medium and additional baryon-number-violating processes are considered. We focus on the time-dependence since it is different for the $n\bar{n}$ transition followed by…

High Energy Physics - Phenomenology · Physics 2008-12-13 V. I. Nazaruk

Recently, it was established that there exists a direct relation between the non-Hermitian skin effects, -strong dependence of spectra on boundary conditions for non-Hermitian Hamiltonians-, and boundary zero modes for Hermitian topological…

Mesoscale and Nanoscale Physics · Physics 2020-07-10 Nobuyuki Okuma , Masatoshi Sato

We establish a steady-state theory for nonlinear optical conductivity in pseudo-Hermitian systems. We derive compact formulas for the first and second order conductivity tensors in both the velocity and length gauges and prove their exact…

Mesoscale and Nanoscale Physics · Physics 2025-10-09 S. Sajad Dabiri , Reza Asgari

Non-Hermitian systems with parity-time symmetry have been found to exhibit real spectra of eigenvalues, indicating a balance between the loss and gain. However, such a balance is not only dependent on the magnitude of loss and gain, but…

Optics · Physics 2020-09-29 Liyou Luo , Jie Luo , Hongchen Chu , Yun Lai

The Non-Linear Sigma Model (NLSM) is an example of a field theory on a target space exhibiting intricate geometry. One remarkable characteristic of the NLSM is asymptotic freedom, which triggers interest in perturbative calculations. In the…

High Energy Physics - Lattice · Physics 2024-12-04 Paolo Baglioni , Francesco Di Renzo

A class of non-Hermitian quadratic su(2) Hamiltonians having an anti-linear symmetry is constructed. This is achieved by analysing the possible symmetries of such systems in terms of automorphisms of the algebra. In fact, different…

Quantum Physics · Physics 2011-06-15 Paulo E. G. Assis

The solutions of the time independent Schrodinger equation for non-Hermitian (NH) Hamiltonians have been extensively studied and calculated in many different fields of physics by using L^2 methods that originally have been developed for the…

Quantum Physics · Physics 2009-11-11 Ido Gilary , Avner Fleischer , Nimrod Moiseyev