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Related papers: Unitary quantum evolution for time-dependent quasi…

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In quantum mechanics the unitary evolution is most often described in a pre-selected Hilbert space ${\cal H}^{(textbook)}$ in which, due to the Stone theorem, the Schr\"odinger-picture Hamiltonian is self-adjoint,…

Quantum Physics · Physics 2017-09-05 Miloslav Znojil

Quantum computing's potential for exponential speedup is fundamentally limited by decoherence, a phenomenon arising from environmental interactions. Non-Hermitian quantum mechanics, particularly $PT$-symmetric systems, offers a novel…

Quantum Physics · Physics 2025-11-25 Duttatreya , Ipsika Mohanty , Sanjib Dey

We present a systematic method for dealing with time dependent quantum dynamics, based on the quantum brachistochrone and matrix mechanics. We derive the explicit time dependence of the Hamiltonian operator for a number of constrained…

Quantum Physics · Physics 2012-10-29 Peter G. Morrison

A series of recent papers ``Faster than Hermitian Quantum Mechanics'' and related articles made a point of the possibility of a non-Hermitian, but PT-symmetric, operator to play the role of a Hamiltonian. In particular, they show that with…

Quantum Physics · Physics 2008-04-15 Mark J. Everitt , Shaaban Khalil , Alexandre M. Zagoskin

It is shown, that quantum theory with complex evolutionary time parameter and non-Hermitian Hamiltonian structure can be used for natural unification of quantum and thermodynamic principles. The theory is postulated as analytical in respect…

High Energy Physics - Theory · Physics 2007-05-23 Vadim V. Asadov , Oleg V. Kechkin

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

We prove under certain assumptions that there exists a solution of the Schrodinger or the Heisenberg equation of motion generated by a linear operator H acting in some complex Hilbert space H, which may be unbounded, not symmetric, or not…

Mathematical Physics · Physics 2015-06-17 Shinichiro Futakuchi , Kouta Usui

Optimal realizations of quantum technology tasks lead to the necessity of a detailed analytical study of the behavior of a $d$-level quantum system (qudit) under a time-dependent Hamiltonian. In the present article, we introduce a new…

Quantum Physics · Physics 2020-05-05 Elena R. Loubenets , Christian Käding

We present a model of discrete quantum evolution based on quantum correlations between the evolving system and a reference quantum clock system. A quantum circuit for the model is provided, which in the case of a constant Hamiltonian is…

Quantum Physics · Physics 2016-07-06 A. Boette , R. Rossignoli , N. Gigena , M. Cerezo

The ordinary time-dependent perturbation theory of quantum mechanics, that describes the interaction of a stationary system with a time-dependent perturbation, predicts that the transition probabilities induced by the perturbation are…

Quantum Physics · Physics 2017-10-11 S. Longhi , G. Della Valle

The Heisenberg picture of the minisuperspace model is considered. The suggested quantization scheme interprets all the observables including the Universe scale factor as the (quasi)Heisenberg operators. The operators arise as a result of…

General Relativity and Quantum Cosmology · Physics 2011-11-09 S. L. Cherkas , V. L. Kalashnikov

The time-dependent pseudo-Hermitian formulation of quantum mechanics allows to study open system dynamics in analogy to Hermitian quantum systems. In this setting, we show that the notion of holonomic quantum computation can equally be…

Quantum Physics · Physics 2019-10-23 Julien Pinske , Lucas Teuber , Stefan Scheel

We consider a class of (possibly nondiagonalizable) pseudo-Hermitian operators with discrete spectrum, showing that in no case (unless they are diagonalizable and have a real spectrum) they are Hermitian with respect to a semidefinite inner…

Quantum Physics · Physics 2015-06-26 G. Scolarici , L. Solombrino

A time operator is a Hermitian operator that is canonically conjugate to a given Hamiltonian. For a particle in 1-dimension, a Hamiltonian conjugate operator in position representation can be obtained by solving a hyperbolic second-order…

Quantum Physics · Physics 2024-09-06 Ralph Adrian E. Farrales , Herbert B. Domingo , Eric A. Galapon

Time-local master equations are more generally applicable than is often recognised, but at first sight it would seem that they can only safely be used in time intervals where the time evolution is invertible. Using the Jaynes-Cummings…

Quantum Physics · Physics 2013-01-10 Daniel Maldonado-Mundo , Patrik Ohberg , Brendon W. Lovett , Erika Andersson

We propose a new point of view regarding the problem of time in quantum mechanics, based on the idea of replacing the usual time operator $\mathbf{T}$ with a suitable real-valued function $T$ on the space of physical states. The proper…

An apparent paradox is resolved that concerns the existence of time operators which have been derived for the quantum harmonic oscillator. There is an apparent paradox because, although a time operator is canonically conjugate to the…

Quantum Physics · Physics 2007-05-23 Alex Granik , H. Ralph Lewis

We address the problem of identifying the (nonstationary) quantum systems that admit supersymmetric dynamical invariants. In particular, we give a general expression for the bosonic and fermionic partner Hamiltonians. Due to the…

Quantum Physics · Physics 2009-11-07 Ali Mostafazadeh

A commonly adopted relational account of time evolution in generally-covariant systems, and more specifically in quantum cosmology, is argued to be unsatisfactory, insofar as it describes evolution relative to observed readings of a clock…

General Relativity and Quantum Cosmology · Physics 2011-03-10 Ian D. Lawrie

The phenomenon of quantum phase transition is considered in the special case in which the evolution laws remain unitary and in which the bound-state energies remain observable. The conventional Hermiticity of observables is lost at the…

Quantum Physics · Physics 2018-04-24 Miloslav Znojil