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We present a new quantum adiabatic theorem that allows one to rigorously bound the adiabatic timescale for a variety of systems, including those described by unbounded Hamiltonians. Our bound is geared towards the qubit approximation of…

Quantum Physics · Physics 2024-01-17 Evgeny Mozgunov , Daniel A. Lidar

Accurate simulation of the non-adiabatic dynamics of molecules in excited electronic states is key to understanding molecular photo-physical processes. Here we present a novel method, based on a semiclassical approximation, that is as…

Chemical Physics · Physics 2016-05-24 Alexander White , Sergei Tretiak , Dmitry Mozyrsky

We provide a method for analytically constructing high-accuracy templates for the gravitational wave signals emitted by compact binaries moving in inspiralling eccentric orbits. By contrast to the simpler problem of modeling the…

General Relativity and Quantum Cosmology · Physics 2009-11-10 Thibault Damour , Achamveedu Gopakumar , Bala R. Iyer

We consider slowly evolving, i.e. ADIABATIC, operational regime within a transmission level (continental scale) natural gas pipeline system. This allows us to introduce a set of nodal equations of reduced complexity describing gas…

Systems and Control · Computer Science 2017-08-04 Michael Chertkov , Alexander Korotkevich

We revisit the complex time method for the application to quantum dynamics as an exceptional point is encircled in the parameter space of the Hamiltonian. The basic idea of the complex time method is using complex contour integration to…

Quantum Physics · Physics 2022-07-13 Petra Ruth Kapralova-Zdanska

We study the $2e^-2e^+$ equal-mass charge-neutral four-body system in the adiabatic hyperspherical framework. The lowest few adiabatic potentials are calculated for zero orbital angular momentum, positive parity, and charge conjugation…

Atomic Physics · Physics 2015-06-23 K. M. Daily , Javier von Stecher , Chris H. Greene

An analysis of the characteristic function of Gaussian quadratic forms is presented in [1] to study the performance of multichannel communication systems. This technical report reviews this analysis, obtaining alternative expressions to…

Information Theory · Computer Science 2012-12-04 Unai Fernández-Plazaola , Eduardo Martos-Naya , José F. Paris , José T. Entrambasaguas

For a theoretical understanding of the reactivity of complex chemical systems, relative energies of stationary points on potential energy hypersurfaces need to be calculated to high accuracy. Due to the large number of intermediates present…

Chemical Physics · Physics 2018-10-30 Gregor N. Simm , Markus Reiher

We present a self-contained theoretical and computational framework for dynamics following photoexcitation in quantum dots near planar interfaces. A microscopic Hamiltonian parameterized by first principles calculations is merged with a…

Mesoscale and Nanoscale Physics · Physics 2015-06-15 Kuljit S. Virk , Mark S. Hybertsen , David R. Reichman

When electron correlations are important it is often necessary to use numerical methods to solve the Hamiltonian for a finite system (cluster) "exactly". Unfortunately, such methods are restricted to small systems. We propose to combine the…

Strongly Correlated Electrons · Physics 2009-10-31 Maciej M. Maska

The discrete formulation of adiabatic quantum computing is compared with other search methods, classical and quantum, for random satisfiability (SAT) problems. With the number of steps growing only as the cube of the number of variables,…

Quantum Physics · Physics 2009-11-07 Tad Hogg

Let $H(t)=(1-t/T)H_0 + (t/T)H_1$, $t\in [0,T]$, be the Hamiltonian governing an adiabatic quantum algorithm, where $H_0$ is diagonal in the Hadamard basis and $H_1$ is diagonal in the computational basis. We prove that $H_0$ and $H_1$ must…

Quantum Physics · Physics 2008-06-02 Lawrence M. Ioannou , Michele Mosca

A quantum Monte Carlo method of determining Jastrow-Slater wave functions for which the energy is stationary with respect to variations in the single-particle orbitals is presented. A potential is determined by a least-squares fitting of…

Condensed Matter · Physics 2007-05-23 Stephen Fahy , Claudia Filippi

We consider the problem of constrained motion along a conic path under a given external potential function. The model is described as a second-class system capturing the behavior of a certain class of specific quantum field theories. By…

Quantum Physics · Physics 2022-05-18 R. L. Caires , S. L. Oliveira , R. Thibes

In this paper we fill the gap in previous works by proving the formula for entanglement-assisted capacity of quantum channel with additive constraint (such as bosonic Gaussian channel). The main tools are the coding theorem for…

Quantum Physics · Physics 2009-11-07 A. S. Holevo

We demonstrate how to determine numerically nearly exact orthonormal orbitals that are optimal for evaluation of the energy of arbitrary (correlated) states of atoms and molecules by minimization of the energy Lagrangian. Orbitals are…

The dynamical systems invariant under gauge transformations with higher order time derivatives of the gauge parameter are considered from the Hamiltonian point of view. We investigate the consequences of the basic requirements that the…

High Energy Physics - Theory · Physics 2009-11-13 M. N. Stoilov

A one-electron Schroedinger equation based on special one-electron potentials for atoms is shown to exist that produces orbitals for an arbitrary molecule that are sufficiently accurate to be used without modification to construct single-…

Chemical Physics · Physics 2022-05-16 Jerry L. Whitten

Adiabatic transformation can be approximated as alternating unitary operators of a Hamiltonian and its parameter derivative as proposed in a gate-based approach to counterdiabatic driving (van Vreumingen, arXiv:2406.08064). In this paper,…

Quantum Physics · Physics 2024-07-18 Takuya Hatomura

Classical polarizable approaches have become the gold standard for simulating complex systems and processes in the condensed phase. These methods describe intrinsically dissipative polarizable media, requiring a formal definition within the…