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We consider three different approaches to analyze the quantum mechanical problems in multi-well potentials: i) the standard matrix diagonalization technique in the basis sets of harmonic oscillator eigenfunctions or plain waves; ii) the…

Quantum Physics · Physics 2020-12-11 V. P. Berezovoj , Yu. L. Bolotin , V. A. Cherkaskiy , M. I. Konchantnyi

We present a quantum algorithm to solve systems of linear equations of the form $A\mathbf{x}=\mathbf{b}$, where $A$ is a tridiagonal Toeplitz matrix and $\mathbf{b}$ results from discretizing an analytic function, with a circuit complexity…

Quantum Physics · Physics 2022-01-17 Almudena Carrera Vazquez , Ralf Hiptmair , Stefan Woerner

We introduce a new numerical method for solving time-harmonic acoustic scattering problems. The main focus is on plane waves scattered by smoothly varying material inhomogeneities. The proposed method works for any frequency $\omega$, but…

Numerical Analysis · Mathematics 2022-01-14 Anton Arnold , Sjoerd Geevers , Ilaria Perugia , Dmitry Ponomarev

We present an extension of constrained-path auxiliary-field quantum Monte Carlo (CP-AFQMC) for the treatment of correlated electronic systems coupled to phonons. The algorithm follows the standard CP-AFQMC approach for description of the…

Strongly Correlated Electrons · Physics 2021-03-24 Joonho Lee , Shiwei Zhang , David R. Reichman

In this paper we propose and analyze an energy stable numerical scheme for the Cahn-Hilliard equation, with second order accuracy in time and the fourth order finite difference approximation in space. In particular, the truncation error for…

Numerical Analysis · Mathematics 2017-12-19 Kelong Cheng , Wenqiang Feng , Cheng Wang , Steven M. Wise

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…

We apply the Quasi Monte Carlo (QMC) and recursive numerical integration methods to evaluate the Euclidean, discretized time path-integral for the quantum mechanical anharmonic oscillator and a topological quantum mechanical rotor model.…

High Energy Physics - Lattice · Physics 2016-01-26 A. Ammon , A. Genz , T. Hartung , K. Jansen , H. Leövey , J. Volmer

We introduce various optimization schemes for highly accurate calculation of the eigenvalues and the eigenfunctions of the one-dimensional anharmonic oscillators. We present several methods of analytically fixing the nonlinear variational…

Mathematical Physics · Physics 2012-12-07 Pouria Pedram

Two physically important potentials (Manning-Rosen and P\"oschl-Teller) are considered for the ro-vibrational energy in diatomic molecules. An improved new approximation is invoked for the centrifugal term, which is then used for their…

Quantum Physics · Physics 2022-05-23 Debraj Nath , Amlan K. Roy

A central challenge of applying near-term quantum optimization algorithms to industrially relevant problems is the need to incorporate complex constraints. In general, such constraints cannot be easily encoded in the circuit, and the…

Quantum Physics · Physics 2023-04-18 Tianyi Hao , Ruslan Shaydulin , Marco Pistoia , Jeffrey Larson

In this paper, we consider numerical approximations for the viscous Cahn-Hilliard equation with hyperbolic relaxation. This type of equations processes energy-dissipative structure. The main challenge in solving such a diffusive system…

Numerical Analysis · Mathematics 2017-12-18 Xiaofeng Yang , Jia Zhao

Using the technique of tridiagonal representation approach; for the first time, we extend this method to study quantum systems with literally perturbed Hamiltonians. Specifically, we consider a quantum system in a 3D spherical oscillator…

Quantum Physics · Physics 2022-12-12 Tunde Joseph Taiwo

We present a new filtered low-regularity Fourier integrator for the cubic nonlinear Schr\"odinger equation based on recent time discretization and filtering techniques. For this new scheme, we perform a rigorous error analysis and establish…

Numerical Analysis · Mathematics 2019-02-20 Alexander Ostermann , Frédéric Rousset , Katharina Schratz

Perturbation theory (PT) might be one of the most powerful and fruitful tools for both physicists and chemists, which evoked an explosion of applications with the blooming of atomic and subatomic physics. Even though PT is well-used today,…

Quantum Physics · Physics 2023-05-16 Junxu Li , Barbara A. Jones , Sabre Kais

Approximate bound state solutions of the Dirac equation with the Hulth\'en plus a new generalized ring-shaped (RS) potential are obtained for any arbitrary -state. The energy eigenvalue equation and the corresponding two-component wave…

Quantum Physics · Physics 2013-08-01 Sameer M. Ikhdair , Majid Hamzavi

We investigate the increasing stability of the inverse Schr\"{o}dinger potential problem with integer power type nonlinearities at a large wavenumber. By considering the first order linearized system with respect to the unknown potential…

Analysis of PDEs · Mathematics 2024-10-07 Sen Zou , Shuai Lu , Boxi Xu

By use of the recently derived $universal$ discrete imaginary-time propagator of the harmonic oscillator, both thermodynamic and Hamiltonian energies can be given analytically, and evaluated numerically at each imaginary time step, for…

Quantum Physics · Physics 2024-07-01 Siu A. Chin

We apply the asymptotic iteration method (AIM) to obtain the solutions of Schrodinger equation in the presence of Poschl-Teller (PT) potential. We also obtain the solutions of Dirac equation for the same potential under the condition of…

Quantum Physics · Physics 2015-06-16 Sameer M. Ikhdair , Babatunde J. Falaye

Single particles moving in a reflection-asymmetric potential are investigated by solving the Schr\"{o}dinger equation of the reflection-asymmetric Nilsson Hamiltonian with the imaginary time method in 3D lattice space and the harmonic…

Nuclear Theory · Physics 2018-06-04 Yuanyuan Wang , Zhengxue Ren

We present a new technique for efficiently transitioning a quantum system from an initial to a final stationary state in less time than is required by an adiabatic (quasi-static) process. Our approach makes use of Nelson's stochastic…

Quantum Physics · Physics 2024-08-07 Vincent Hardel , Giovanni Manfredi , Paul-Antoine Hervieux , Rémi Goerlich