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In this paper, the out-of-time-order correlators (OTOC) in quantum harmonic oscillators are calculated analytically by second quantization method in perturbative approximation. We consider the coupled harmonic oscillators and anharmonic…

High Energy Physics - Theory · Physics 2023-08-21 Wung-Hong Huang

We study a non-interacting quantum particle, moving on a one-dimensional lattice, which is subjected to repetitive measurements. We investigate the consequence when such motion is interrupted and restarted from the same initial…

Quantum Physics · Physics 2023-03-21 Ranjan Modak , S. Aravinda

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 quantum measurement axiom dictates that physical observables and in particular the Hamiltonian must be diagonalizable and have a real spectrum. For a time-independent Hamiltonian (with a discrete spectrum) these conditions ensure the…

Quantum Physics · Physics 2009-11-13 Ali Mostafazadeh

Conventional weak-coupling perturbation theory suffers from problems that arise from resonant coupling of successive orders in the perturbation series. Multiple-scale perturbation theory avoids such problems by implicitly performing an…

High Energy Physics - Theory · Physics 2009-10-30 Carl M. Bender , Luis M. A. Bettencourt

We obtain the complexity geometry associated with the Hamiltonian of a quantum mechanical system, specifically in cases where the Hamiltonian is explicitly time-dependent. Using Nielsen's geometric formulation of circuit complexity, we…

Quantum Physics · Physics 2025-07-22 Kunal Pal , Kuntal Pal

Generally, natural scientific problems are so complicated that one has to establish some effective perturbation or nonperturbation theories with respect to some associated ideal models. In this Letter, a new theory that combines…

Computational Physics · Physics 2015-05-13 Yuan Gao , S. Y. Lou

We provide a reviewlike introduction into the quantum mechanical formalism related to non-Hermitian Hamiltonian systems with real eigenvalues. Starting with the time-independent framework we explain how to determine an appropriate domain of…

Quantum Physics · Physics 2015-06-26 Carla Figueira de Morisson Faria , Andreas Fring

Conventional weak-coupling Rayleigh-Schr\"odinger perturbation theory suffers from problems that arise from resonant coupling of successive orders in the perturbation series. Multiple-scale analysis, a powerful and sophisticated…

High Energy Physics - Theory · Physics 2009-10-30 Carl M. Bender , Luis M. A. Bettencourt

Keeping in view the ordering ambiguity that arises due to the presence of position-dependent effective mass in the kinetic energy term of the Hamiltonian, a general scheme for obtaining algebraic solutions of quantum mechanical systems with…

Quantum Physics · Physics 2016-06-29 Naila Amir , Shahid Iqbal

We show that quantum-interference phenomena can be realized for the dissipative nonlinear systems exhibiting hysteresis-cycle behavior and quantum chaos. Such results are obtained for a driven dissipative nonlinear oscillator with…

Quantum Physics · Physics 2015-05-19 T. V. Gevorgyan , A. R. Shahinyan , G. Yu. Kryuchkyan

Using operator ordering techniques based on BCH-like relations of the su(1,1) Lie algebra and a time-splitting approach,we present an alternative method of solving the dynamics of a time-dependent quantum harmonic oscillator for any initial…

Quantum Physics · Physics 2021-03-26 D. M. Tibaduiza , L. B. Pires , D. Szilard , A. L. C. Rego , C. A. D. Zarro , C. Farina

In this work, we develop a theoretical description of the collective behavior of interacting dipolar planar rotors by using time independent perturbation theory and a small angle quadratic approximation. The ground state properties for both…

Chemical Physics · Physics 2026-04-21 Estêvão V. B. de Oliveira , Muhammad Shaeer Moeed , Pierre-Nicholas Roy

We present a simple and efficient method to incorporate anharmonic effects in the vibrational \textcolor{black}{analyses} of molecules within density functional theory (DFT) calculations. This approach is closely related to the traditional…

The non-Hermitian models, which are symmetric under parity (P) and time-reversal (T) operators, are the cornerstone for the fabrication of new ultra-sensitive optoelectronic devices. However, providing the gain in such systems usually…

Quantum Physics · Physics 2023-03-17 Hamed Ghaemi-Dizicheh , Hamidreza Ramezani

With the aim to solve the time-dependent Schr\"{o}dinger equation associated to a time-dependent non-Hermitian Hamiltonian, we introduce a unitary transformation that maps the Hamiltonian to a time-independent $\mathcal{PT}$-symmetric one.…

Quantum Physics · Physics 2021-12-28 F. Kecita , A. Bounames , M. Maamache

In this work we present the simplest generic form of the propagator for the time-dependent quadratic Hamiltonian. We manifest the simplicity of our method by giving explicitly the propagators for a free particle in time-dependent electric…

Quantum Physics · Physics 2014-12-12 Gal Harari , Yacob Ben-Aryeh , Ady Mann

We employ the technique of perturbative analytic null bootstrap to obtain the energy eigenvalues and ladder operators of the sextic anharmonic oscillator up to second order in the coupling. We confirm our results by deriving the same from…

Quantum Physics · Physics 2023-09-26 Renjan Rajan John , Krishna Priya R

The perturbation method is an approximation scheme with a solvable leading order. The standard way is to choose a non-interacting sector for the leading order. The adaptive perturbation method improves the solvable part by using all…

High Energy Physics - Theory · Physics 2022-10-17 Chen-Te Ma

We propose a procedure to obtain exact analytical solutions to the time-dependent Schr\"{o}dinger equations involving explicit time-dependent Hermitian Hamitonians from solutions to time-independent non-Hermitian Hamiltonian systems and the…

Quantum Physics · Physics 2017-01-25 Andreas Fring , Thomas Frith