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Related papers: Integrals for lower bounds to the exact energy

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A new method for generating analytical expression of quantum Hamiltonian from non-linear differential equation with stationary energy level has been formulated.Further calculation of energy levels have been carried out analytically using…

Quantum Physics · Physics 2014-12-30 Biswanath Rath , P. Mallick

A method for finding the exact analytical solutions for the bulk and edge energy levels and corresponding eigenstates for all commensurate Aubry-Andr\'e/Harper single-particle models under open boundary conditions is presented here, both…

Strongly Correlated Electrons · Physics 2020-01-29 A. M Marques , R. G. Dias

A systematic search for superintegrable quantum Hamiltonians describing the interaction between two particles with spin 0 and 1/2, is performed. We restrict to integrals of motion that are first-order (matrix) polynomials in the components…

Mathematical Physics · Physics 2012-10-11 P. Winternitz , I. Yurdusen

We obtain the exact energy spectrum of nonuniform mass particles for a collection of Hamiltonians in a three-dimensional approach to a quantum dot. By considering a set of generalized Schr\"odinger equations with different orderings between…

Mesoscale and Nanoscale Physics · Physics 2023-11-27 R. M. Lima , H. R. Christiansen

Estimating the ground-state energy of Hamiltonians is a fundamental task for which it is believed that quantum computers can be helpful. Several approaches have been proposed toward this goal, including algorithms based on quantum phase…

Quantum Physics · Physics 2025-11-26 Dhrumil Patel , Daniel Koch , Saahil Patel , Mark M. Wilde

The discrete energy-eigenvalues of two nucleons interacting with a finite-range nuclear force and confined to a harmonic potential are used to numerically reconstruct the free-space scattering phase shifts. The extracted phase shifts are…

Nuclear Theory · Physics 2014-11-21 Thomas Luu , Martin Savage , Achim Schwenk , James P. Vary

In this work, we provide a complete description of the scattering matrix elements and electron energy spectrum in one dimensional PT-symmetric hybrid finite systems, using the characteristic determinant approach. We present an analytical…

Mesoscale and Nanoscale Physics · Physics 2026-05-05 Vladimir Gasparian , Esther Jódar , Antonio Pérez-Garrido

An algebraic procedure to find extremal density matrices for any Hamiltonian of a qudit system is established. The extremal density matrices for pure states provide a complete description of the system, that is, the energy spectra of the…

Mathematical Physics · Physics 2016-10-03 Armando Figueroa , Julio A. López-Saldívar , Octavio Castaños , Ramón López-Peña

The processing of quantum information always has a cost in terms of physical resources such as energy or time. Determining the resource requirements is not only an indispensable step in the design of practical devices - the resources need…

Quantum Physics · Physics 2022-12-23 Yuxiang Yang , Renato Renner , Giulio Chiribella

A simple and efficient variational method is introduced to accelerate the convergence of the eigenenergy computations for a Hamiltonian H with singular potentials. Closed-form analytic expressions in N dimensions are obtained for the matrix…

Mathematical Physics · Physics 2009-11-10 Nasser Saad , Richard L. Hall , Qutaibeh D. Katatbeh

A variational solution procedure is reported for the many-particle no-pair Dirac-Coulomb-Breit Hamiltonian aiming at a parts-per-billion (ppb) convergence of the atomic and molecular energies, described within the fixed nuclei…

Quantum Physics · Physics 2024-06-19 Péter Jeszenszki , Dávid Ferenc , Edit Mátyus

By application of a straightforward variational procedure we derive a simple, analytic upper bound on the ground-state energy eigenvalue of a semirelativistic Hamiltonian for (one or two) spinless particles which experience some…

High Energy Physics - Phenomenology · Physics 2009-10-28 Wolfgang Lucha , Franz F. SCHÖberl

We propose accurate computable error bounds for quantities of interest in plane-wave electronic structure calculations, in particular ground-state density matrices and energies, and interatomic forces. These bounds are based on an…

Numerical Analysis · Mathematics 2022-10-20 Eric Cancès , Geneviève Dusson , Gaspard Kemlin , Antoine Levitt

The article presents an introductory review of quantum algorithms for non-relativisitc as well as relativistic four component molecular energy calculations developed in past few years.

Quantum Physics · Physics 2012-03-29 Libor Veis , Jiří Pittner

In this paper methods for calculations of multi-center integrals of squared Coulomb potentials and Slater-type orbitals (STO) are derived. These integrals are necessary for accurate lower bounds to energy levels of molecular systems. All…

Chemical Physics · Physics 2022-02-10 Sohei Ashida

It is shown that by means of the approach based on the Quantum Hamilton-Jacobi equation, it is possible to modify the WKB expressions for the energy levels of quantum systems, when incorrect, obtaining exact WKB-like formulae. This extends…

Quantum Physics · Physics 2022-04-07 Mario Fusco Girard

Estimating ground state energies of many-body Hamiltonians is a central task in many areas of quantum physics. In this work, we give quantum algorithms which, given any $k$-body Hamiltonian $H$, compute an estimate for the ground state…

Preparing the ground state of a given Hamiltonian and estimating its ground energy are important but computationally hard tasks. However, given some additional information, these problems can be solved efficiently on a quantum computer. We…

Quantum Physics · Physics 2020-12-16 Lin Lin , Yu Tong

Advantages of using a low-energy effective theory to study bound state properties are briefly discussed, and a nonperturbative implementation of such an effective theory is described within the context of nonrelativistic quantum mechanics.…

High Energy Physics - Phenomenology · Physics 2009-10-31 Richard Hill

An exact quantization rule for the Schr\"{o}dinger equation is presented. In the exact quantization rule, in addition to $N\pi$, there is an integral term, called the quantum correction. For the exactly solvable systems we find that the…

Computational Physics · Physics 2015-06-26 Zhong-Qi Ma , Bo-Wei Xu