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Related papers: Bootstrapping PT symmetric Hamiltonians

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A quantum state for being an eigenstate of some local Hamiltonian should be constraint by zero energy variance and consequently, the constraint is rather strong that a single eigenstate may uniquely determine the Hamiltonian. For…

Quantum Physics · Physics 2024-12-17 Xu-Dan Xie , Zheng-Yuan Xue , Dan-Bo Zhang

The Hamiltonian H specifies the energy levels and time evolution of a quantum theory. A standard axiom of quantum mechanics requires that H be Hermitian because Hermiticity guarantees that the energy spectrum is real and that time evolution…

High Energy Physics - Theory · Physics 2008-11-26 Carl M. Bender

The method of positive commutators, developed for zero temperature problems over the last twenty years, has been an essential tool in the spectral analysis of Hamiltonians in quantum mechanics. We extend this method to positive…

Mathematical Physics · Physics 2009-11-10 Marco Merkli

In recent decades, an important shift has taken place with the growing role of non-Hermitian quantum mechanics. What makes this framework remarkable is that the eigenvalues of the Hamiltonians involved can still be real, just as in the…

Quantum Physics · Physics 2025-09-30 Maamache Mustapha

Quantum theory can be formulated with certain non-Hermitian Hamiltonians. An anti-linear involution, denoted by PT, is a symmetry of such Hamiltonians. In the PT-symmetric regime the non-Hermitian Hamiltonian is related to a Hermitian one…

High Energy Physics - Theory · Physics 2020-10-02 Daniel Areán , Karl Landsteiner , Ignacio Salazar Landea

It is shown that the standard formulation of quantum mechanics in terms of Hermitian Hamiltonians is overly restrictive. A consistent physical theory of quantum mechanics can be built on a complex Hamiltonian that is not Hermitian but…

Quantum Physics · Physics 2008-12-18 Carl M. Bender , Dorje C. Brody , Hugh F. Jones

We survey some of the main conceptual developments in the study of PT-symmetric and pseudo-Hermitian Hamiltonian operators that have taken place during the past ten years or so. We offer a precise mathematical description of a quantum…

Quantum Physics · Physics 2015-05-19 Ali Mostafazadeh

A re-formulated, non-Hermitian version of the Witten's supersymmetric quantum mechanics is presented. Its use of pseudo-Hermitian (so called PT symmetric) Hamiltonians is reviewed and illustrated via several forms of an innovated…

High Energy Physics - Theory · Physics 2007-05-23 Miloslav Znojil

Non-hermiticity presents a vast newly opened territory that harbors new physics and applications such as lasing and sensing. However, only non-Hermitian systems with real eigenenergies are stable, and great efforts have been devoted in…

Other Condensed Matter · Physics 2022-10-25 Russell Yang , Jun Wei Tan , Tommy Tai , Jin Ming Koh , Linhu Li , Stefano Longhi , Ching Hua Lee

We consider a two-level system such as a two-level atom, interacting with a cavity field mode in the rotating wave approximation, when the atomic transition frequency or the field mode frequency is periodically driven in time. We show that…

Recently, much research has been carried out on Hamiltonians that are not Hermitian but are symmetric under space-time reflection, that is, Hamiltonians that exhibit PT symmetry. Investigations of the Sturm-Liouville eigenvalue problem…

High Energy Physics - Theory · Physics 2007-05-23 Carl M. Bender , Dorje C. Brody , Lane P. Hughston , Bernhard K. Meister

It is believed that unbroken PT symmetry is sufficient to guarantee that the spectrum of a non-Hermitian Hamiltonian is real. We prove that this is not true. We study a Hamiltonian with complex spectrum for which PT symmetry is not…

Quantum Physics · Physics 2007-05-23 C. Yuce

In most introductory courses on quantum mechanics one is taught that the Hamiltonian operator must be Hermitian in order that the energy levels be real and that the theory be unitary (probability conserving). To express the Hermiticity of a…

Quantum Physics · Physics 2008-11-26 Carl M. Bender

We study non Hermitian quantum systems in noncommutative space as well as a \cal{PT}-symmetric deformation of this space. Specifically, a \mathcal{PT}-symmetric harmonic oscillator together with iC(x_1+x_2) interaction is discussed in this…

High Energy Physics - Theory · Physics 2009-03-12 Pulak Ranjan Giri , P Roy

Examples are given of non-Hermitian Hamiltonian operators which have a real spectrum. Some of the investigated operators are expressed in terms of the generators of the Weil-Heisenberg algebra. It is argued that the existence of an…

Quantum Physics · Physics 2009-09-29 João da Providência , Natália Bebiano , João Pinheiro da Providência

It has recently been shown that a non-Hermitian Hamiltonian H possessing an unbroken PT symmetry (i) has a real spectrum that is bounded below, and (ii) defines a unitary theory of quantum mechanics with positive norm. The proof of…

High Energy Physics - Theory · Physics 2014-11-18 Carl M. Bender , Dorje C. Brody , Hugh F. Jones

In this paper, a non-trivial system governed by a continuum PT-symmetric Hamiltonian is discussed. We show that this Hamiltonian is iso-spectral to the simple harmonic oscillator. We find its eigenfunctions and the path in the complex plane…

Quantum Physics · Physics 2022-08-09 Lawrence Mead , David Garfinkle , Sungwook Lee

We propose giving the mathematical concept of the pseudospectrum a central role in quantum mechanics with non-Hermitian operators. We relate pseudospectral properties to quasi-Hermiticity, similarity to self-adjoint operators, and basis…

Spectral Theory · Mathematics 2015-11-30 D. Krejcirik , P. Siegl , M. Tater , J. Viola

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 current applications of non-Hermitian but ${\cal PT}-$symmetric Hamiltonians $H$ cover several, mutually not too closely connected subdomains of quantum physics. Mathematically, the split between the open and closed systems can be…

Quantum Physics · Physics 2021-10-29 Miloslav Znojil