Quantum Boltzmann Equation Self-Consistent-Field for the Entropic Regularization of Mean-Field Singularities
- URL: http://arxiv.org/abs/2608.14979v2
- Date: Wed, 19 Aug 2026 13:18:05 GMT
- Title: Quantum Boltzmann Equation Self-Consistent-Field for the Entropic Regularization of Mean-Field Singularities
- Abstract summary: We present a Quantum Boltzmann Equation self-consistent-field (QBE-SCF) formulation for molecular electronic structure.<n>For spatial degeneracies, zero-temperature kinetic ergodicity fractionalizes the active space to recover the Generalized Valence Bond (GVB) limit.<n>These results establish kinetic relaxation as a synthesis of single-reference electronic structure and quantum statistical mechanics.
- Score: 0.0
- License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/
- Abstract: We present a Quantum Boltzmann Equation self-consistent-field (QBE-SCF) formulation for molecular electronic structure in which the one-electron reduced density matrix is propagated in an atomic orbital basis and relaxed by a Bhatnagar-Gross-Krook collision operator toward a Fermi-Dirac equilibrium defined by the instantaneous Fock matrix. At stationarity, the converged density and Fock matrices satisfy $[\mathbf{F},\mathbf{P}]=0$, the Hartree-Fock condition. While the zero-temperature equilibrium target reduces to the integer Aufbau projector, the damped collision operator ensures the steady-state density matrix is not necessarily idempotent. This kinetic relaxation affords a dual pathway to resolve mean-field singularities. For spatial degeneracies, such as H$_3$ symmetric dissociation, zero-temperature kinetic ergodicity fractionalizes the active space to recover the Generalized Valence Bond (GVB) limit. For the conical intersection in BeH$_2$ and the H$_4$ structural distortion ($D_{2h} \rightarrow D_{4h} \rightarrow D_{2h}$), finite-temperature entropic regularization recovers correlated adiabatic surfaces from a real-valued single-reference density. By maintaining stable numerical convergence across basis-set hierarchies and resolving static correlation without multi-reference wavefunctions, these results establish kinetic relaxation as a synthesis of single-reference electronic structure and quantum statistical mechanics.
Related papers
- Learning the Kohn-Sham map with neural operators for quasi-linear scaling density functional theory [57.90994363143731]
Kohn--Sham density functional theory (DFT) underpins electronic-structure simulations.<n>Repeated orbital diagonalizations lead to cubic scaling, restricting quantum calculations to modest scales only.<n>We develop a learning target for orbital-free DFT that maps a Kohn--Sham potential directly to the corresponding density and noninteracting kinetic energy.
arXiv Detail & Related papers (2026-08-24T23:05:42Z) - Stochastic Counterdiabatic Driving via Biorthogonal Liouvillian Eigenmodes [42.668742604089324]
Escorted free energy simulations address the non-adiabatic lag by engineering control fields $mathbfu$ that eliminate the lag.<n>We construct a complementary numerical framework based on gauge-type transforms instead of generalized coordinate transforms.<n>We show that the counterdiabatic condition is satisfied to machine precision, with the non-adiabatic lag suppressed by roughly twelve orders of magnitude.
arXiv Detail & Related papers (2026-07-27T13:08:14Z) - Confinement Versus Screening in the Schwinger Model on AdS$_2$ from Bosonization and Tensor Networks [0.0]
We analyze confinement and screening in single-flavor quantum electrodynamics (QED$$) on two-dimensional anti-de Sitter space.<n>The theory is formulated in two frames adapted to distinct choices of a preferred time coordinate: the Schwarzschild frame, associated with the Boulware vacuum, and the global AdS$$ frame, associated with the global AdS$$ vacuum.<n>We perform extensive numerical simulations of the static potential and the electric flux-tube profile for varying fermion masses, which we match to the continuum prediction.
arXiv Detail & Related papers (2026-07-21T18:00:02Z) - Split-quaternionic structure and canonical quantization of the Bateman dual oscillator [0.0]
We develop a split-quaternionic formulation consistent from the classical equations through ordinary complex canonical quantization.<n>A formal trace over the auxiliary coordinate is compared with high-temperature Caldeira--Leggett dynamics, clarifying that the doubled model is a coherent zero-noise embedding.
arXiv Detail & Related papers (2026-07-17T21:33:05Z) - Fault tolerant computation of the static structure factor and finite size effects [43.936586633107396]
We develop a quantum post-processing strategy for the leading two-body finite-size correction.<n>After one-body shell effects are reduced by twist averaging, the dominant residual error is controlled by long-wavelength density fluctuations.<n>We also introduce adaptive global and local binary search procedures for identifying the infrared fitting window used to reconstruct the two-body finite size error correction.
arXiv Detail & Related papers (2026-06-26T05:31:08Z) - Quantum simulation of the Liouville equation in classical mechanics with discontinuous potential via Schrödingerization [42.22857110018992]
We develop quantum simulation algorithms for the Liouville equation of classical mechanics with discontinuous potential.<n>We combine Hamiltonian-preserving schemes by Jin and Wen in Commun. Math. Sci. 3(3), 285-315 (2005) with the Schrdingerization method, which embeds the resulting nonunitary semi-discrete dynamics into a unitary Schrdinger type system.
arXiv Detail & Related papers (2026-06-13T02:49:05Z) - Shattering the Symmetry Trap in Fixed-Ansatz VQE: An Accelerated ADAPT-VQE Study of Three Pillar Molecules under Bravyi-Kitaev Mapping [0.0]
We show how ADAPT-VQE framework shatters structural limitations across three distinct electronic and geometric molecular pillars.<n>Our numerical results show that the accelerated ADAPT-VQE framework achieves instant, exact Full Configuration Interaction.<n>This study establishes a robust, hardware-efficient path for simulating strongly correlated, highly polarized triatomic chemical environments.
arXiv Detail & Related papers (2026-06-04T10:13:23Z) - End-to-End Molecular Dynamics with a Langevin Thermostat on Quantum Circuits [0.0]
We construct a quantum-circuit framework for finite-temperature molecular dynamics in the canonical ensemble (NVT)<n>The classical nuclear phase-space distribution is encoded as a Koopman--von Neumann (KvN) wave function, and canonical state preparation is formulated as Langevin-type Fokker--Planck relaxation.
arXiv Detail & Related papers (2026-05-28T16:05:54Z) - Kramers-Kronig Relations for Vector-Valued Hardy Spaces in Non-Markovian Open Quantum Dynamics [1.8867357521563244]
We organize the analysis around three objects -- the memory kernel, the reduced-state propagator, and the effective kernel.<n>For the kernel, under standard bath hypotheses, we prove membership in the vector-valued Hardy space Hp_+ and derive rigorous KK relations.<n>For the effective kernel, we derive a perturbative modified KK relation with UHP corrections at zeros of the reduce d-state propagator.
arXiv Detail & Related papers (2026-04-18T16:26:40Z) - Fault-tolerant simulation of the electronic structure using Projector Augmented-Waves and Bloch orbitals [43.936586633107396]
We present the Bloch--UPAW framework that combines Bloch-orbital $k$-space structure with unitary projector-augmented-wave augmentation.<n>We derive a linear-combination-of-unitaries decomposition and a block-encoding circuit suitable for qubitization.<n>Asymptotically, the Toffoli cost scales as $mathcalO(N_k3)$ when refining the $k$-mesh and as $mathcalO(N_a3.5)$ when enlarging the supercell.
arXiv Detail & Related papers (2026-04-13T23:46:58Z) - Comparison of the standard and dressed-picture master equations for the quantum Rabi model in the ultrastrong coupling regime [78.55450146498553]
This chapter investigates the effects of relaxation and dephasing on the quantum Rabi model in the ultrastrong coupling regime.<n>It provides explicit formulas to implement and numerically solve the resulting nonunitary dynamics.
arXiv Detail & Related papers (2026-04-10T01:22:07Z) - Quantum optomechanics of lossy bodies: general approach and structured squeezed vacuum effects [51.56484100374058]
We investigate the overall optomechanical force experienced by a macroscopic lossy object in free space under external quantum illumination.<n>By driving the scattering field with an anisotropic, multimode squeezed vacuum state, the spatial profile of the electromagnetic quantum fluctuations can be engineered to exhibit broken rotational symmetry.<n>We establish a general formalism for macroscopic quantum optomechanics that operates beyond the constraints of thermal equilibrium.
arXiv Detail & Related papers (2026-04-07T13:25:43Z) - Analysis of the Single Reference Coupled Cluster Method for Electronic
Structure Calculations: The Full Coupled Cluster Equations [2.3271703838711972]
We introduce a new well-posedness analysis for the single reference coupled cluster method based on the invertibility of the CC derivative.
Preliminary numerical experiments indicate that the constants that appear in our estimates are a significant improvement over those obtained from the local monotonicity approach.
arXiv Detail & Related papers (2022-12-24T17:29:43Z) - Resolving Correlated States of Benzyne on a Quantum Computer with an
Error-Mitigated Quantum Contracted Eigenvalue Solver [0.0]
We show that a contraction of the Schr"odinger equation is solved for the two-electron reduced density matrix (2-RDM)
In contrast to the traditional variational quantum eigensolver, the contracted quantum eigensolver solves an integration (or contraction) of the many-electron Schr"odinger equation onto the two-electron space.
arXiv Detail & Related papers (2021-03-11T18:58:43Z) - Probing eigenstate thermalization in quantum simulators via
fluctuation-dissipation relations [77.34726150561087]
The eigenstate thermalization hypothesis (ETH) offers a universal mechanism for the approach to equilibrium of closed quantum many-body systems.
Here, we propose a theory-independent route to probe the full ETH in quantum simulators by observing the emergence of fluctuation-dissipation relations.
Our work presents a theory-independent way to characterize thermalization in quantum simulators and paves the way to quantum simulate condensed matter pump-probe experiments.
arXiv Detail & Related papers (2020-07-20T18:00:02Z)
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.