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Dynamically encircling an exceptional point (EP) in parity-time (PT) symmetric systems shows an interesting chiral dynamics, leading to asymmetric mode switching in which the output modes are different when the encircling direction is…

Optics · Physics 2019-10-16 Xu-Lin Zhang , Tianshu Jiang , Hong-Bo Sun , C. T. Chan

The Feshbach-type reduction of the Hilbert space to the physically most relevant "model" subspace is suggested as a means of a formal unification of the standard quantum mechanics with its recently proposed PT symmetric modification. The…

Quantum Physics · Physics 2015-06-26 Miloslav Znojil

One of the challenges of the modern photonics is to develop all-optical devices enabling increased speed and energy efficiency for transmitting and processing information on an optical chip. It is believed that the recently suggested…

We consider bright solitons supported by a symmetric inhomogeneous defocusing nonlinearity growing rapidly enough toward the periphery of the medium, combined with an antisymmetric gain-loss profile. Despite the absence of any symmetric…

Optics · Physics 2015-06-22 Yaroslav V. Kartashov , Boris A. Malomed , Lluis Torner

The time evolution of a system with a time-dependent non-Hermitian Hamiltonian is in general unstable with exponential growth or decay. A periodic driving field may stabilize the dynamics because the eigenphases of the associated Floquet…

Quantum Physics · Physics 2015-06-11 Jiangbin Gong , Qing-hai Wang

While non-Hermitian systems are normally constructed through incoherent coupling to a larger environment, recent works have shown that under certain conditions coherent couplings can be used to similar effect. We show that this new paradigm…

Applied Physics · Physics 2022-10-21 Noah Flemens , Jeffrey Moses

The spontaneous breaking of parity-time ($\mathcal{PT}$) symmetry yields rich critical behavior in non-Hermitian systems, and has stimulated much interest, albeit most previous studies were performed within the single-particle or mean-field…

Quantum Gases · Physics 2025-12-23 Jian-Song Pan , Wei Yi , Jiangbin Gong

In this paper, we investigate the dynamics of the Bloch vector of a single two-level atom which interacts with a single quantized electromagnetic field mode according to the Jaynes-Cummings model, where the field is initially prepared in a…

Quantum Physics · Physics 2008-06-17 Hiroo Azuma

We theoretically study the dynamics of typical optomechanical systems, consisting of a passive optical mode and an active mechanical mode, in the $\mathcal{PT}$- and broken-$\mathcal{PT}$-symmetric regimes. By fully analytical treatments…

Quantum Physics · Physics 2021-12-01 Hai Xu , Deng-Gao Lai , Yi-Bing Qian , Bang-Pin Hou , Adam Miranowicz , Franco Nori

Interactions between a source of light and atoms are ubiquitous in nature. The study of them is interesting on the fundamental level as well as for applications. They are in the core of Quantum Information Processing tasks and in Quantum…

Quantum Physics · Physics 2024-01-11 Borhan Ahmadi , Ricard Ravell Rodríguez , Robert Alicki , Michał Horodecki

The observation that PT-symmetric Hamiltonians can have real-valued energy levels even if they are non-Hermitian has triggered intense activities, with experiments, in particular, focusing on optical systems, where Hermiticity can be broken…

Quantum Physics · Physics 2010-06-10 Henning Schomerus

PT-symmetric scattering systems with balanced gain and loss can undergo a symmetry-breaking transition in which the eigenvalues of the non-unitary scattering matrix change their phase shifts from real to complex values. We relate the…

It is well known that typical PT-symmetric systems suffer symmetry breaking when the strength of the gain-loss terms exceeds a certain critical value. We present a summary of recently published and newly produced results which demonstrate…

Optics · Physics 2018-02-27 Vitaly Lutsky , Eitam Luz , Er'el Granot , Boris A. Malomed

We employ electric circuit networks to study topological states of matter in non-Hermitian systems enriched by parity-time symmetry $\mathcal{PT}$ and chiral symmetry anti-$\mathcal{PT}$ ($\mathcal{APT}$). The topological structure…

We systematically study the parity- and time-reversal (PT) symmetric non-Hermitian version of a quantum network proposed in the paper of Christandl et al. [Phys. Rev. Lett. 92, 187902 (2004)]. The nature of this model shows that it is a…

Quantum Physics · Physics 2013-04-16 X. Z. Zhang , L. Jin , Z. Song

We contemplate the pair of the purely imaginary delta-function potentials on a finite interval with Dirichlet boundary conditions. The two parameter model exhibits nicely the expected quantitative features of the unavoided level crossing…

Quantum Physics · Physics 2007-05-23 Vit Jakubsky , Miloslav Znojil

We study the spectral stability of a 2D discrete Schr\"{o}dinger equation on a square lattice, in the simultaneous presence of a fractional Laplacian and $\cal{PT}$ symmetry. For that purpose, we compute the plane-wave spectrum in closed…

Pattern Formation and Solitons · Physics 2022-11-16 Mario I. Molina

Many indefinite-metric (often called pseudo-Hermitian or PT-symmetric) quantum models H prove "physical" (i.e., Hermitian with respect to an innovated, ad hoc scalar product) inside a characteristic domain of parameters D. This means that…

Quantum Physics · Physics 2007-05-23 Miloslav Znojil

The interplay between topology and quantum criticality has given rise to the notion of symmetry-enriched criticality, which has attracted considerable attention in recent years. In this Letter, we demonstrate that parity time (PT) symmetry…

Quantum Physics · Physics 2026-05-15 Kuang-Hung Chou , Xue-Jia Yu , Po-Yao Chang

The study of a particle with position-dependent effective mass (pdem), within a double heterojunction is extended into the complex domain --- when the region within the heterojunctions is described by a non Hermitian ${\cal{PT}}$ symmetric…

Quantum Physics · Physics 2015-06-04 Anjana Sinha