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Related papers: PT Symmetry and the Sign Problem

200 papers

We find that a broken PT-symmetry operator when interacts with suitable Hermitian operator, new system becomes completely un-broken PT symmetry. Further on varying the contribution of Hermiticity one can delay or control the broken…

Quantum Physics · Physics 2020-04-14 Biswanath Rath

Canonical quantum mechanics postulates Hermitian Hamiltonians to ensure real eigenvalues. Counterintuitively, a non-Hermitian Hamiltonian, satisfying combined parity-time (PT) symmetry, could display entirely real spectra above some…

Optics · Physics 2025-01-23 Jianming Wen , Xiaoshun Jiang , Liang Jiang , Min Xiao

The Hamiltonian $H={1\over2} p^2+{1\over2}m^2x^2+gx^2(ix)^\delta$ with $\delta,g\geq0$ is non-Hermitian, but the energy levels are real and positive as a consequence of ${\cal PT}$ symmetry. The quantum mechanical theory described by $H$ is…

High Energy Physics - Theory · Physics 2009-11-07 Carl M. Bender , Stefan Boettcher , Peter N. Meisinger , Qinghai Wang

The concept of parity-time (PT) symmetry originates from the framework of quantum mechanics, where if the Hamiltonian operator satisfies the commutation relation with the parity and time operators, it shows all real eigen-energy spectrum.…

Quantum Physics · Physics 2021-02-03 Wei-Chao Gao , Chao Zheng , Lu Liu , Tiejun Wang , Chuan Wang

Real-to-complex spectral transitions and the associated spontaneous symmetry breaking of eigenstates are central to non-Hermitian physics, yet a comprehensive and universal theory that precisely describes the underlying physical mechanisms…

Quantum Physics · Physics 2025-06-23 Zhuo-Ting Cai , Hai-Dong Li , Wei Chen

A quantum system governed by a non-Hermitian Hamiltonian may exhibit zero temperature phase transitions that are driven by interactions, just as its Hermitian counterpart, raising the fundamental question how non-Hermiticity affects quantum…

Quantum Physics · Physics 2024-12-10 Eduard Naichuk , Jeroen van den Brink , Flavio S. Nogueira

The dynamics of an open quantum system with balanced gain and loss is not described by a PT-symmetric Hamiltonian but rather by Lindblad operators. Nevertheless the phenomenon of PT-symmetry breaking and the impact of exceptional points can…

Quantum Physics · Physics 2021-05-21 Dorje C. Brody

A non-Hermitian PT-symmetric version of the kicked top is introduced to study the interplay of quantum chaos with balanced loss and gain. The classical dynamics arising from the quantum dynamics of the angular momentum expectation values…

Quantum Physics · Physics 2021-01-15 Steve Mudute-Ndumbe , Eva-Maria Graefe

A pair of coupled quantum harmonic oscillators, one subject to a gain one to a loss, is a paradigmatic setup to implement PT-symmetric, non-Hermitian Hamiltonians in that one such Hamiltonian governs the mean-field dynamics for equal gain…

Quantum Physics · Physics 2019-07-03 Federico Roccati , Salvatore Lorenzo , G. Massimo Palma , Francesco Ciccarello

Three ways of constructing a non-Hermitian matrix with possible all real eigenvalues are discussed. They are PT symmetry, pseudo-Hermiticity, and generalized PT symmetry. Parameter counting is provided for each class. All three classes of…

Quantum Physics · Physics 2012-12-11 Jia-wen Deng , Uwe Guenther , Qing-hai Wang

One-dimensional scattering mediated by non-Hermitian Hamiltonians is studied. A schematic set of models is used which simulate two point interactions at a variable strength and distance. The feasibility of the exact construction of the…

Quantum Physics · Physics 2008-06-26 Miloslav Znojil

Finite-density QCD and many other field theories with sign problems have a $\mathcal{PT}$-type symmetry. After a brief introduction to $\mathcal{PT}$-symmetric field theories, a real dual representation for $\mathcal{PT}$-symmetric scalar…

High Energy Physics - Lattice · Physics 2021-10-28 Moses A. Schindler , Stella T. Schindler , Michael C. Ogilvie

We present a phase space study of non-Hermitian Hamiltonian with $\mathcal{PT}$-symmetry based on the Wigner distribution function. For an arbitrary complex potential, we derive a generalized continuity equation for the Wigner function flow…

Quantum Physics · Physics 2016-05-25 Ludmila Praxmeyer , Popo Yang , Ray-Kuang Lee

Parity-time ($\mathcal{PT}$) symmetric systems are classical, gain-loss systems whose dynamics are governed by non-Hermitian Hamiltonians with exceptional-point (EP) degeneracies. The eigenvalues of a $\mathcal{PT}$-symmetric Hamiltonian…

Quantum Physics · Physics 2021-08-27 Kaustubh S. Agarwal , Yogesh N. Joglekar

In the presence of Lindblad decoherence, i.e. dissipative effects in an open quantum system due to interaction with an environment, we examine the transition probabilities between the eigenstates in the two-level quantum system described by…

Quantum Physics · Physics 2024-04-24 Tommy Ohlsson , Shun Zhou

Parity-time ($\mathcal{PT}$) symmetry is a cornerstone of non-Hermitian physics as it ensures real energies for stable experimental realization of non-Hermitian phenomena. In this work, we propose $\mathcal{PT}$ symmetry as a paradigm for…

Mesoscale and Nanoscale Physics · Physics 2024-03-22 Zhoutao Lei , Ching Hua Lee , Linhu Li

A consistent physical theory of quantum mechanics can be built on a complex Hamiltonian that is not Hermitian but instead satisfies the physical condition of space-time reflection symmetry (PT symmetry). Thus, there are infinitely many new…

High Energy Physics - Theory · Physics 2009-11-10 Carl M. Bender , Dorje C. Brody , Hugh F. Jones

In multiparticle quantum interference, bosons show rather generally the tendency to bunch together, while fermions can not. This behavior, which is rooted in the different statistics of the particles, results in a higher coincidence rate…

Quantum Physics · Physics 2020-12-15 Stefano Longhi

A quantum-mechanical theory is PT-symmetric if it is described by a Hamiltonian that commutes with PT, where the operator P performs space reflection and the operator T performs time reversal. A PT-symmetric Hamiltonian often has a…

High Energy Physics - Theory · Physics 2013-05-30 Carl M. Bender , V. Branchina , Emanuele Messina

In 1998, Carl Bender challenged the perceived wisdom of quantum mechanics that the Hamiltonian operator describing any quantum mechanical system has to be Hermitian. He showed that Hamiltonians that are invariant under combined parity-time…