Adiabatic perturbation theory for two-component systems with one heavy component

• URL: http://arxiv.org/abs/2310.09189v2
• Date: Thu, 20 Jun 2024 14:19:44 GMT
• Title: Adiabatic perturbation theory for two-component systems with one heavy component
• Authors: Ryan Requist,
• Abstract summary: An effective Hamiltonian that is accurate to second order in the inverse heavy mass is derived. The most salient application of the theory is to systems of electrons and nuclei.
• Score: 0.0
• License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/
• Abstract: Perturbation theory with respect to the kinetic energy of the heavy component of a two-component quantum system is introduced. An effective Hamiltonian that is accurate to second order in the inverse heavy mass is derived. It contains a new form of kinetic energy operator with a Hermitian mass tensor and a complex-valued vector potential. All of the potentials in the effective Hamiltonian can be expressed in terms of covariant derivatives and a resolvent operator. The most salient application of the theory is to systems of electrons and nuclei. The accuracy of the theory is verified numerically in a model diatomic molecule and analytically in a vibronic coupling model.

Related papers

• Large Electron Model: A Universal Ground State Predictor [0.0]
  We introduce a single neural network model that produces variational wavefunctions of interacting electrons over the entire Hamiltonian parameter manifold.<n>Our results establish a foundation model method for material discovery that is grounded in the variational principle.
  arXiv  Detail & Related papers  (2026-03-02T19:29:12Z)
• Double-pair Coulomb(-Breit) photon correction to the correlated relativistic energy [0.0]
  The simplest quantum-electrodynamical corrections are computed to the no-pair Dirac-Coulomb(-Breit) energy of two-spin-1/2-fermion systems.<n>Results are reported for two-electron atoms with a clamped nucleus and positronium-like genuine two-particle systems.
  arXiv  Detail & Related papers  (2025-10-06T08:12:38Z)
• Quantum Potential from the Material Derivative of the Osmotic Velocity: A Two-Fluid Madelung Framework [0.0]
  We derive the quantum potential directly from the material derivative of the osmotic velocity.<n>We formulate a two-fluid model that reproduces the Madelung equations.
  arXiv  Detail & Related papers  (2025-09-02T22:33:01Z)
• Multi-Photon Quantum Rabi Models with Center-of-Mass Motion [45.73541813564926]
  We introduce a rigorous, second-quantized framework for describing multi-$Lambda$-atoms in a cavity.<n>A key feature of our approach is the systematic application of a Hamiltonian averaging theory to the atomic field operators.<n>A significant finding is the emergence of a particle-particle interaction mediated by ancillary states.
  arXiv  Detail & Related papers  (2025-07-07T09:50:48Z)
• Mesoscopic theory of the Josephson junction [44.99833362998488]
  We derive a mesoscopic theory of the Josephson junction from non-relativistic scalar electrodynamics. By providing an ab initio derivation of the charge qubit Hamiltonian, we progress toward the quantum engineering of superconducting circuits at the subnanometer scale.
  arXiv  Detail & Related papers  (2024-11-08T15:29:07Z)
• Hamiltonian truncation tensor networks for quantum field theories [42.2225785045544]
  We introduce a tensor network method for the classical simulation of continuous quantum field theories. The method is built on Hamiltonian truncation and tensor network techniques. One of the key developments is the exact construction of matrix product state representations of global projectors.
  arXiv  Detail & Related papers  (2023-12-19T19:00:02Z)
• Quantum hydrodynamics of coupled electron-nuclear systems [0.0]
  The quantum dynamics of electron-nuclear systems is analyzed from the perspective of the exact factorization of the wavefunction. For pure states this is accomplished with a quantum hydrodynamical description of the nuclear dynamics and electronic density operators tied to the fluid elements. The theory presented here bridges exact quantum dynamics with several mixed quantum-classical approaches currently in use to tackle non-adiabatic molecular problems.
  arXiv  Detail & Related papers  (2023-10-12T23:26:27Z)
• Effective quantum electrodynamics: One-dimensional model of the relativistic hydrogen-like atom [0.0]
  We consider a one-dimensional effective quantum electrodynamics model of the relativistic hydrogen-like atom. The present work may be considered as a step toward the development of a quantum-chemistry effective QED theory of atoms and molecules.
  arXiv  Detail & Related papers  (2023-05-23T07:55:01Z)
• Quantum vibrational mode in a cavity confining a massless spinor field [91.3755431537592]
  We analyse the reaction of a massless (1+1)-dimensional spinor field to the harmonic motion of one cavity wall. We demonstrate that the system is able to convert bosons into fermion pairs at the lowest perturbative order.
  arXiv  Detail & Related papers  (2022-09-12T08:21:12Z)
• Variational Adiabatic Gauge Transformation on real quantum hardware for effective low-energy Hamiltonians and accurate diagonalization [68.8204255655161]
  We introduce the Variational Adiabatic Gauge Transformation (VAGT) VAGT is a non-perturbative hybrid quantum algorithm that can use nowadays quantum computers to learn the variational parameters of the unitary circuit. The accuracy of VAGT is tested trough numerical simulations, as well as simulations on Rigetti and IonQ quantum computers.
  arXiv  Detail & Related papers  (2021-11-16T20:50:08Z)
• Coupled Cluster Downfolding Methods: the effect of double commutator terms on the accuracy of ground-state energies [0.0]
  We discuss the impact of higher-order terms originating in double commutators on the appearance of the downfolded Hamiltonians. We demonstrate the efficiency of the many-body expansions involving single and double commutators for the unitary extension of the downfolded Hamiltonians.
  arXiv  Detail & Related papers  (2021-10-22T21:49:45Z)
• Relativistic aspects of orbital and magnetic anisotropies in the chemical bonding and structure of lanthanide molecules [60.17174832243075]
  We study the electronic and ro-vibrational states of heavy homonuclear lanthanide Er2 and Tm2 molecules by applying state-of-the-art relativistic methods. We were able to obtain reliable spin-orbit and correlation-induced splittings between the 91 Er2 and 36 Tm2 electronic potentials dissociating to two ground-state atoms.
  arXiv  Detail & Related papers  (2021-07-06T15:34:00Z)
• Relativistic density-functional theory based on effective quantum electrodynamics [0.0]
  A relativistic density-functional theory based on a Fock-space effective quantum-electrodynamics (QED) Hamiltonian is developed. A Kohn-Sham scheme is formulated in a quite similar way to non-relativistic density-functional theory. The usual no-pair Kohn-Sham scheme is obtained as a well-defined approximation to this relativistic density-functional theory.
  arXiv  Detail & Related papers  (2021-02-20T22:43:08Z)
• Evolution of a Non-Hermitian Quantum Single-Molecule Junction at Constant Temperature [62.997667081978825]
  We present a theory for describing non-Hermitian quantum systems embedded in constant-temperature environments. We find that the combined action of probability losses and thermal fluctuations assists quantum transport through the molecular junction.
  arXiv  Detail & Related papers  (2021-01-21T14:33:34Z)
• On the Extension of Linear Damping to Quantum Mechanics through Fractionary Momentum Operators Pt. I [2.5582075465437972]
  Three important associated 1 dimensional problems were solved: the free particle case, the infinite potential well, and the harmonic potential. We conclude that there exists a relationship between fractional kinetic energy and special relativity energies, that remains unclear and needs further exploration.
  arXiv  Detail & Related papers  (2020-07-15T02:12:06Z)
• Quantum decoherence by Coulomb interaction [58.720142291102135]
  We present an experimental study of the Coulomb-induced decoherence of free electrons in a superposition state in a biprism electron interferometer close to a semiconducting and metallic surface. The results will enable the determination and minimization of specific decoherence channels in the design of novel quantum instruments.
  arXiv  Detail & Related papers  (2020-01-17T04:11:44Z)

This list is automatically generated from the titles and abstracts of the papers in this site.

This site does not guarantee the quality of this site (including all information) and is not responsible for any consequences.