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Related papers: Vibrational Heat-Bath Configuration Interaction

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The linear and quadratic interactions of an impurity vibrational mode coupled with a heat bath are investigated with a non-Markovian equation of motion for the reduced density matrix valid for the initial, intermediate and kinetic stages of…

Quantum Physics · Physics 2008-02-03 D. Kilin , M. Schreiber

This study focuses on extending the concept of weak signal enhancement from dynamical systems based on vibrational resonance of nonlinear systems, to non-smooth systems. A Van der Pol- Duffing oscillator with a one-sided barrier, subjected…

Chaotic Dynamics · Physics 2024-07-26 Somnath Roy , Sayan Gupta

We use selected configuration interaction to calculate the zero-temperature mid-infrared (2800-3800 cm$^{-1}$) vibrational spectra of a water monomer, dimer, trimer, and hexamer in its cage and prism geometries. We use the recently…

Chemical Physics · Physics 2025-09-18 Henry K. Tran , Timothy C. Berkelbach

Even when starting with a very poor initial guess, the iterative configuration interaction (iCI) approach can converge from above to full CI very quickly by constructing and diagonalizing a small Hamiltonian matrix at each…

Chemical Physics · Physics 2020-01-07 Ning Zhang , Wenjian Liu , Mark R. Hoffmann

We give a thorough analysis of the convergence properties of the configuration-interaction method as applied to parabolic quantum dots among other systems, including \emph{a priori} error estimates. The method converges slowly in general,…

Computational Physics · Physics 2013-05-29 Simen Kvaal

Variational quantum eigensolver (VQE) solves the ground state problem of a given Hamiltonian by finding the parameters of a quantum circuit ansatz that minimizes the Hamiltonian expectation value. Among possible quantum circuit ans\"{a}tze,…

Quantum Physics · Physics 2024-01-31 Chae-Yeun Park

A master equation for the deformed quantum harmonic oscillator interacting with a dissipative environment, in particular with a thermal bath, is derived in the microscopic model by using perturbation theory. The coefficients of the master…

Quantum Physics · Physics 2009-11-13 A. Isar , W. Scheid

We present the meta-VQE, an algorithm capable to learn the ground state energy profile of a parametrized Hamiltonian. By training the meta-VQE with a few data points, it delivers an initial circuit parametrization that can be used to…

Quantum Physics · Physics 2021-06-01 Alba Cervera-Lierta , Jakob S. Kottmann , Alán Aspuru-Guzik

We present a quantum information-inspired ansatz for the variational quantum eigensolver (VQE) and demonstrate its efficacy in calculating ground-state energies of atomic systems. Instead of adopting a heuristic approach, we start with an…

Quantum Physics · Physics 2025-08-19 Abdul Kalam , Prasenjit Deb , Akitada Sakurai , B. K. Sahoo , V. S. Prasannaa , B. P. Das

Methyl benzoate (MB) is studied as a model compound for the development of new IR pulse schemes with possible applicability to biomolecules. Anharmonic vibrational modes of MB are calculated on different level (MP2, SCS, CCSD(T) with…

Chemical Physics · Physics 2014-01-03 Kiran Sankar Maiti , Christoph Scheurer

Variational quantum eigensolver(VQE) typically minimizes energy with hybrid quantum-classical optimization, which aims to find the ground state. Here, we propose a VQE by minimizing energy variance, which is called as variance-VQE(VVQE).…

Quantum Physics · Physics 2020-06-30 Dan-Bo Zhang , Zhan-Hao Yuan , Tao Yin

Contact breaking and Hertzian interactions between grains can both give rise to nonlinear vibrational response of static granular packings. We perform molecular dynamics simulations at constant energy in 2D of frictionless bidisperse disks…

Soft Condensed Matter · Physics 2014-04-03 Carl F. Schreck , Corey S. O'Hern , Mark D. Shattuck

We use extensive first-principles quantum mechanical calculations to show that, although the static lattice and harmonic vibrational energies are almost identical, the anharmonic vibrational energy of hexagonal ice is significantly lower…

Materials Science · Physics 2015-08-13 Edgar A. Engel , Bartomeu Monserrat , Richard J. Needs

Theoretical predictions of photochemical processes are essential for interpreting and understanding spectral features. Reliable quantum dynamics calculations of vibronic systems require precise modeling of anharmonic effects in the…

Chemical Physics · Physics 2026-04-24 Valentin Barandun , Nina Glaser , Markus Reiher

Hot-atoms reactions mechanisms bring about reaction rates which are several orders of magnitude higher than those expected in the case of ad-atoms which have thermalized with the surface. This paper addresses the issue of a possible…

Materials Science · Physics 2015-06-11 Massimo Tomellini

We consider a d-dimensional crystal with an arbitrary harmonic interaction and an anharmonic on-site potential, with stochastic Langevin heat bath at each site. We develop an integral formalism for the correlation functions that is suitable…

Statistical Mechanics · Physics 2009-11-10 Emmanuel Pereira , Ricardo Falcao

A scheme for improving the sensitivity of quantum thermometry is proposed where the sensing quantum system used to recover the temperature of an external bath is dynamically coupled with an external ancilla (a meter) via a Hamiltonian term…

Quantum Physics · Physics 2018-10-31 Alexander Holm Kiilerich , Antonella De Pasquale , Vittorio Giovannetti

Transport in a one-dimensional symmetric device can be activated by the combination of thermal noise and a bi-harmonic drive. For the study case of an overdamped Brownian particle diffusing on a periodic one-dimensional substrate, we…

Statistical Mechanics · Physics 2009-11-11 M. Borromeo , F. Marchesoni

The Variational Quantum Eigensolver (VQE) is a quantum algorithm used to find the ground state energy of a given Hamiltonian. The key component of VQE is the ansatz, which is a trial wavefunction that the algorithm uses to approximate the…

Quantum Physics · Physics 2023-10-05 Yilin Shen

A communication protocol is proposed in which quantum state transfer is mediated by a vibrational exciton. We consider two distant molecular groups grafted on the sides of a lattice. These groups behave as two quantum computers where the…

Quantum Physics · Physics 2015-06-03 Vincent J. C. Pouthier