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The time-evolution operator obtained from the fractional-time Schr\"{o}dinger equation (FTSE) is said to be non-unitary since it does not preserve the norm of the vector state in time. As done in the time-dependent non-Hermitian quantum…

Quantum Physics · Physics 2022-11-23 D. Cius , L. Menon , M. A. F. dos Santos , A. S. M. de Castro , F. M. Andrade

I will provide a pedagogical introduction to non-Hermitian quantum systems that are PT-symmetric, that is they are left invariant under a simultaneous parity transformation (P) and time-reversal (T). I will explain how generalised versions…

Quantum Physics · Physics 2023-02-27 Andreas Fring

We propose a simple quantum algorithm for simulating highly oscillatory quantum dynamics, which does not require complicated quantum control logic for handling time-ordering operators. To our knowledge, this is the first quantum algorithm…

Quantum Physics · Physics 2022-04-20 Dong An , Di Fang , Lin Lin

It is shown that, in the framework of non-relativistic quantum mechanics, any conserved Hermitian operator (which may depend explicitly on the time) is the generator of a one-parameter group of unitary symmetries of the Hamiltonian and…

Quantum Physics · Physics 2015-10-19 G. F. Torres del Castillo , J. E. Herrera Flores

A possible method to investigate non-Hermitian Hamiltonians is suggested through finding a Hermitian operator $\eta_+$ and defining the annihilation and creation operators to be $\eta_+$-pseudo-Hermitian adjoint to each other. The operator…

Quantum Physics · Physics 2014-06-06 Jun-Qing Li , Yan-Gang Miao , Zhao Xue

We derive the leading asymptotic behavior and build a new series representation for the Fredholm determinant of integrable integral operators appearing in the representation of the time and distance dependent correlation functions of…

Mathematical Physics · Physics 2015-04-30 K. K. Kozlowski

We demonstrate how electric fields with arbitrary time profile can be used to control the time-dependent parameters of spin and orbital exchange Hamiltonians. Analytic expressions for the exchange constants are derived from a time-dependent…

Strongly Correlated Electrons · Physics 2017-03-10 Martin Eckstein , Johan H. Mentink , Philipp Werner

In this paper we have obtained the exact eigenstates of a two dimensional damped harmonic oscillator in time dependent noncommutative space. It has been observed that for some specific choices of the damping factor and the time dependent…

Quantum Physics · Physics 2020-12-09 Manjari Dutta , Shreemoyee Ganguly , Sunandan Gangopadhyay

The evolution operator U(t) for a time-independent parity-time-symmetric systems is well studied in the literature. However, for the non-Hermitian time-dependent systems, a closed form expression for the evolution operator is not available.…

Mathematical Physics · Physics 2018-11-22 Bijan Bagchi

Being chosen as a differential operator of a special form, metric $\eta$ operator becomes unitary equivalent to a one-dimensional Hermitian Hamiltonian with a natural supersymmetric structure. We show that fixing the superpartner of this…

Mathematical Physics · Physics 2015-06-05 Boris F. Samsonov

While the Hamiltonians used in standard quantum mechanics are Hermitian, it is also possible to extend the theory to non-Hermitian Hamiltonians. Particularly interesting are non-Hermitian Hamiltonians satisfying parity-time (PT) symmetry,…

Quantum Physics · Physics 2024-02-05 Feliks Kivelä , Shruti Dogra , Gheorghe Sorin Paraoanu

We outline a method based on successive canonical transformations which yields a product expansion for the evolution operator of a general (possibly non-Hermitian) Hamiltonian. For a class of such Hamiltonians this expansion involves a…

Quantum Physics · Physics 2009-10-31 Ali Mostafazadeh

A diagonalizable non-Hermitian Hamiltonian having a real spectrum may be used to define a unitary quantum system, if one modifies the inner product of the Hilbert space properly. We give a comprehensive and essentially self-contained review…

Quantum Physics · Physics 2015-05-13 Ali Mostafazadeh

In this paper, we present a proof-of-concept quantum algorithm for simulating time-dependent Hamiltonian evolution by reducing the problem to simulating a time-independent Hamiltonian in a larger space using a discrete clock Hamiltonian…

Quantum Physics · Physics 2025-07-28 Zecheng Li , Chunhao Wang

Non-Hermiticity in quantum Hamiltonians leads to nonunitary time evolution and possibly complex energy eigenvalues, which can lead to a rich phenomenology with no Hermitian counterpart. In this work, we study the dynamics of an exactly…

Quantum Physics · Physics 2023-10-25 Karin Sim , Nicolò Defenu , Paolo Molignini , R. Chitra

We generalize the Milne quantization condition to non-Hermitian systems. In the general case the underlying nonlinear Ermakov-Milne-Pinney equation needs to be replaced by a nonlinear integral differential equation. However, when the system…

Quantum Physics · Physics 2015-09-16 Sanjib Dey , Andreas Fring , Laure Gouba

A $(K+1)-$plet of non-Hermitian and time-dependent operators (say, $\Lambda_j(t)$, $j=0,1,\ldots,K$) can be interpreted as the set of observables characterizing a unitary quantum system. What is required is the existence of a self-adjoint…

Quantum Physics · Physics 2023-08-21 Miloslav Znojil

Aim of this paper is to show the possible significance, and usefulness, of various non-selfadjoint operators for suitable Observables in non relativistic and relativistic quantum mechanics, and in quantum electrodynamics. More specifically,…

Quantum Physics · Physics 2010-05-10 Erasmo Recami , Vladislav S. Olkhovsky , Sergei P. Maydanyuk

We represent low dimensional quantum mechanical Hamiltonians by moderately sized finite matrices that reproduce the lowest O(10) boundstate energies and wave functions to machine precision. The method extends also to Hamiltonians that are…

Quantum Physics · Physics 2015-06-03 Johann Foerster , Alejandro Saenz , Ulli Wolff

This work presents a tensorial approach to constructing data-driven reduced-order models corresponding to semi-discrete partial differential equations with canonical Hamiltonian structure. By expressing parameter-varying operators with…

Numerical Analysis · Mathematics 2025-05-14 Arjun Vijaywargiya , Shane A. McQuarrie , Anthony Gruber
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