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In this article, we investigate periodically driven open quantum systems within the framework of Floquet-Lindblad master equations. Specifically, we discuss Lindblad master equations in the presence of a coherent, time-periodic driving and…

The amplitude of resonant oscillations in a non-Hermitian environment can either decay or grow in time, corresponding to a mode with either loss or gain. When two coupled modes have a specific difference between their loss or gain, a…

Classical Physics · Physics 2025-11-07 N. J. Lambert , A. Schumer , J. J. Longdell , S. Rotter , H. G. L. Schwefel

We study a class of bifurcations generically occurring in dynamical systems with non-mutual couplings ranging from models of coupled neurons to predator-prey systems and non-linear oscillators. In these bifurcations, extended attractors…

Chaotic Dynamics · Physics 2023-08-11 Cheyne Weis , Michel Fruchart , Ryo Hanai , Kyle Kawagoe , Peter B. Littlewood , Vincenzo Vitelli

We reveal a novel topological property of the exceptional points in a two-level parity-time symmetric system and then propose a scheme to detect the topological exceptional points in the system, which is embedded in a larger Hilbert space…

Quantum Physics · Physics 2017-08-02 Jian Xu , Yan-Xiong Du , Wei Huang , Dan-Wei Zhang

An exceptional point is a special point in parameter space at which two (or more) eigenvalues and eigenvectors coincide. The discovery of exceptional points within mechanical and optical systems has uncovered peculiar effects in their…

Quantum Physics · Physics 2025-04-24 C. A. Downing , V. A. Saroka

The Lindblad equation describes the dissipative time evolution of a density matrix that characterizes an open quantum system in contact with its environment. The widespread ensemble interpretation of a density matrix requires its time…

Quantum Physics · Physics 2020-09-04 Bernd Fernengel , Barbara Drossel

We report a new kind of exceptional points in periodically driven system, called Floquet $\pi$ exceptional points, whose eigenvectors rotate on Bloch sphere and accumulate $\pi$ geometric phase in one time period. The merging of two such…

Mesoscale and Nanoscale Physics · Physics 2024-07-22 Weiwei Zhu

Physical systems with loss or gain feature resonant modes that are decaying or growing exponentially with time. Whenever two such modes coalesce both in their resonant frequency and their rate of decay or growth, a so-called "exceptional…

This work presents an analysis of the evolution of perturbed Bell diagonal states using the equation of motion of steepest-entropy-ascent quantum thermodynamics (SEAQT), the Lindblad equation, and various measures of loss of entanglement.…

Quantum Physics · Physics 2024-08-27 Cesar Damian , Robert Holladay , Adriana Saldana , Michael von Spakovsky

Dynamical encirclement of an Exceptional Point (EP) and corresponding time-asymmetric mode evolution properties due to breakdown in adiabatic theorem have been a key to range of exotic physical effects in various open atomic, molecular and…

Optics · Physics 2019-04-17 Arnab Laha , Sibnath Dey , Harsh K. Gandhi , Abhijit Biswas , Somnath Ghosh

The exceptional point has presented considerably interesting and counterintuitive phenomena associated with nonreciprocity, precision measurement, and topological dynamics. The Liouvillian exceptional point (LEP), involving the interplay of…

Exceptional points (EPs) in non-Hermitian photonics offer singular sensitivity enhancements but have thus far been realized almost exclusively in spatially engineered platforms with fixed geometries and limited tunability. Here we extend EP…

Our aim in this paper is twofold. Firstly, we develop a new asymptotic theory for Floquet exponents. We consider a linear system of differential equations with a time-periodic coefficient matrix. Assuming that the coefficient matrix depends…

Analysis of PDEs · Mathematics 2021-10-18 Habib Ammari , Erik Orvehed Hiltunen , Thea Kosche

Nonequilibrium topological matter has been a fruitful topic of both theoretical and experimental interest. A great variety of exotic topological phases unavailable in static systems may emerge under nonequilibrium situations, often…

Mesoscale and Nanoscale Physics · Physics 2022-04-06 Nannan Ma , Jiangbin Gong

Exceptional points (EPs) are distinct characteristics of non-Hermitian Hamiltonians that have no counterparts in Hermitian systems. In this study, we focus on EPs in continuous systems rather than discrete non-Hermitian systems, which are…

Quantum Physics · Physics 2025-05-13 Y. T. Wang , R. Wang , X. Z. Zhang

Quantum adiabaticity is the evolution of a quantum system that remains close to an instantaneous eigenstate of a time-dependent Hamiltonian. Using Floquet formalism, we derive a rigorous sufficient condition for adiabaticity in closed,…

Quantum Physics · Physics 2026-05-12 Jie Gu , X. -G. Zhang

The exotic physics emerging in non-Hermitian systems with balanced distributions of gain and loss has drawn a great deal of attention in recent years. These systems exhibit phase transitions and exceptional point singularities in their…

Optics · Physics 2021-03-17 Arik Bergman , Robert Duggan , Kavita Sharma , Moshe Tur , Avi Zadok , Andrea Alu

The Liouvillian exceptional points for a quantum Markovian master equation of an oscillator in a generic environment are obtained. They occur at the points when the modified frequency of the oscillator vanishes, whereby the eigenvalues of…

Quantum Physics · Physics 2023-04-17 B. A. Tay

We consider a periodically driven quantum system described by a Hamiltonian which is the product of a slowly varying Hermitian operator $V\left(\boldsymbol{\lambda}\left(t\right)\right)$ and a dimensionless periodic function with zero…

Quantum Physics · Physics 2019-07-31 Viktor Novičenko , Gediminas Juzeliūnas

The mathematical objects employed in physical theories do not always behave well. Einstein's theory of space and time allows for spacetime singularities and Van Hove singularities arise in condensed matter physics, while intensity, phase…

Quantum Physics · Physics 2023-07-10 C. A. Downing , A. Vidiella-Barranco