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Related papers: A variational method from the variance of energy

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We present a cascaded variational quantum eigensolver algorithm that only requires the execution of a set of quantum circuits once rather than at every iteration during the parameter optimization process, thereby increasing the…

Quantum Physics · Physics 2024-03-11 Daniel Gunlycke , C. Stephen Hellberg , John P. T. Stenger

Quantum entanglement is a foundational resource in quantum information science, underpinning applications across physics. However, detecting and quantifying entanglement remains a significant challenge. In this article, we introduce a…

We present a comparison of real-space methods based on regular grids for electronic structure calculations that are designed to have basis set variational properties, using as a reference the conventional method of finite differences (a…

Materials Science · Physics 2009-11-07 Chris-Kriton Skylaris , Oswaldo Dieguez , Peter D. Haynes , Mike C. Payne

One of the key applications for quantum computers will be the simulation of other quantum systems that arise in chemistry, materials science, etc, in order to accelerate the process of discovery. It is important to ask: Can this be achieved…

Quantum Physics · Physics 2017-07-05 Ying Li , Simon C. Benjamin

Variational quantum algorithms are proposed to solve relevant computational problems on near term quantum devices. Popular versions are variational quantum eigensolvers and quantum ap- proximate optimization algorithms that solve ground…

Quantum Physics · Physics 2022-04-15 Lennart Bittel , Martin Kliesch

Quantum state tomography is an integral part of quantum computation and offers the starting point for the validation of various quantum devices. One of the central tasks in the field of state tomography is to reconstruct with high fidelity,…

Quantum Physics · Physics 2022-12-21 Rishabh Gupta , Manas Sajjan , Raphael D. Levine , Sabre Kais

We investigate the Dirac time-dependent variational method using a Gaussian trial functional for an infinite one dimensional system of Bosons interacting through a repulsive contact interaction. The method produces a set of non-linear time…

Condensed Matter · Physics 2009-10-30 Arthur K. Kerman , Paolo Tommasini

This work studies pulse based variational quantum algorithms (VQAs), which are designed to determine the ground state of a quantum mechanical system by combining classical and quantum hardware. In contrast to more standard gate based…

Quantum Physics · Physics 2023-02-01 Robert de Keijzer , Oliver Tse , Servaas Kokkelmans

We discuss a recently proposed analytical formula for the eigenvalues of the Gaussian well and compare it with the analytical expression provided by the variational method with the simplest trial function. The latter yields considerably…

Mathematical Physics · Physics 2015-06-11 Francisco M Fernández , Javier Garcia

Precise variational solutions are given for problems involving diverse fermionic and bosonic $N=2-7$-body systems. The trial wave functions are chosen to be combinations of correlated Gaussians, which are constructed from products of the…

Nuclear Theory · Physics 2008-11-26 K. Varga , Y. Suzuki

An approximation method which combines the perturbation theory with the variational calculation is constructed for quantum mechanical problems. Using the anharmonic oscillator and the He atom as examples, we show that the present method…

Quantum Physics · Physics 2009-10-30 Sang Koo You , Kwang Joe Jeon , Chul Koo Kim , Kyun Nahm

Minimization of the expectation value of energy under the constraints imposed by the uncertainty principle can be a convenient method of solving quantum-mechanical problems.

Quantum Physics · Physics 2012-06-08 A. K. Khitrin

Quantum computing uses the physical principles of very small systems to develop computing platforms which can solve problems that are intractable on conventional supercomputers. There are challenges not only in building the required…

Quantum Physics · Physics 2024-11-19 Dieter Jaksch , Peyman Givi , Andrew J. Daley , Thomas Rung

The continuous variable quantum computing platform constitutes a promising candidate for realizing quantum advantage, as exemplified in Gaussian Boson Sampling. While noise in the experiments makes the computation attainable for classical…

Quantum Physics · Physics 2025-08-11 Jonas Vinther , Michael James Kastoryano

Determining low-energy eigenstates in electronic many-body quantum systems is a key challenge in computational chemistry and condensed-matter physics. Hybrid quantum-classical approaches, such as the Variational Quantum Eigensolver and…

Quantum Physics · Physics 2025-10-27 Hamzat A. Akande , Alexandre Perrin , Bruno Senjean , Matthieu Saubanere

The variational method employing the amplitude and width as collective coordinates of the Klein-Gordon oscillon leads to a dynamical system with unstable periodic orbits that blow up when perturbed. We propose a multiscale variational…

High Energy Physics - Theory · Physics 2023-11-01 I. V. Barashenkov , N. V. Alexeeva

In this paper we present applications of methods from wavelet analysis to polynomial approximations for a number of accelerator physics problems. According to variational approach in the general case we have the solution as a…

Accelerator Physics · Physics 2009-10-31 Antonina N. Fedorova , Michael G. Zeitlin , Zohreh Parsa

The variational perturbation theory for wave functions, which has been shown to work well for bound states of the anharmonic oscillator, is applied to resonance states of the anharmonic oscillator with negative coupling constant. We obtain…

High Energy Physics - Theory · Physics 2009-10-30 T. Tanaka

Variational quantum algorithms aim at harnessing the power of noisy intermediate-scale quantum computers, by using a classical optimizer to train a parameterized quantum circuit to solve tractable quantum problems. The variational quantum…

We develop an alternative approach to time independent perturbation theory in non-relativistic quantum mechanics. The method developed has the advantage to provide in one operation the correction to the energy and to the wave function,…

Quantum Physics · Physics 2013-03-13 J. Martinez-Carranza , F. Soto-Eguibar , H. Moya-Cessa