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The spin-boson model is a paradigm for studying decoherence, relaxation, entanglement and other effects that arise in a quantum system coupled to environmental degrees of freedom. At zero temperature, a localization-delocalization phase…

Quantum Physics · Physics 2015-01-22 Yao Yao , Nengji Zhou , Javier Prior , Yang Zhao

We formulate automated market maker (AMM) \emph{rebalancing} as a binary detection problem and study a hybrid quantum--classical self-attention block, \textbf{Quantum Adaptive Self-Attention (QASA)}. QASA constructs quantum…

Quantum Physics · Physics 2025-09-23 Chi-Sheng Chen , Aidan Hung-Wen Tsai

A phenomenological description for the dynamical spin susceptibility $\chi({\bf q},\omega;T)$ observed in inelastic neutron scattering measurements on powder samples of LiV$_2$O$_4$ is developed in terms of the parametrized self-consistent…

Strongly Correlated Electrons · Physics 2009-11-13 V. Yushankhai , P. Thalmeier , T. Takimoto

A space-time collocation method (STCM) using asymptotically-constant basis functions is proposed and applied to the quantum Hamiltonian constraint for a loop-quantized treatment of the Schwarzschild interior. Canonically, these descriptions…

Computational Physics · Physics 2020-12-02 Alec Yonika , Alfa Heryudono , Gaurav Khanna

The development of a self-consistent thermodynamic theory of quantum systems is of fundamental importance for modern physics. Still, despite its essential role in quantum science and technology, there is no unifying formalism for…

Quantum Physics · Physics 2022-11-30 André Malavazi , Frederico Brito

We develop a new approach for efficient and scalable simulations of measurement and control of quantum systems built upon existing phase-space methods, namely the Truncated Wigner Approximation (TWA). We benchmark against existing…

Quantum Physics · Physics 2024-09-04 Kaiwen Zhu , Zain Mehdi , Joseph J. Hope , Simon A. Haine

We consider here the problem of a "central spin", with spin quantum number $S \gg 1$, interacting with a set of microscopic spins. Interactions between the microscopic spins are ignored. This model describes magnetic grains or magnetic…

Condensed Matter · Physics 2016-08-31 N. V. Prokof'ev , P. C. E. Stamp

In this Letter, we derive a quantum nonlinear sigma model (QNLSM) for quantum Heisenberg antiferromagnets (QHA) with arbitrary S (spin) values. A upper limit of the low temperature is naturally carried out for the reliability of the QNLSM.…

Strongly Correlated Electrons · Physics 2009-11-11 Jianhui Dai , Wei-Min Zhang

The Einstein action for the gravitational field has some properties which make of it, after quantization, a rare prototype of systems with quantum configurations that do not have a classical analogue. Assuming spherical symmetry in order to…

General Relativity and Quantum Cosmology · Physics 2020-06-23 G. Modanese

Quantum thermodynamics is a powerful theoretical tool for assessing the suitability of quantum materials as platforms for novel technologies. In particular, the modeling of quantum cycles allows us to investigate the heat changes and work…

Quantum Physics · Physics 2024-11-20 Vinicius Gomes de Paula , Wanisson S. Santana , Clebson Cruz , Mario Reis

We propose a feasible and effective approach to study quantum thermal transport through anharmonic systems. The main idea is to obtain an {\it effective} harmonic Hamiltonian for the anharmonic system by applying the self-consistent phonon…

Statistical Mechanics · Physics 2016-10-19 Dahai He , Juzar Thingna , Jian-Sheng Wang , Baowen Li

Spin plays a fundamental role in understanding electronic structure, yet many real-space wavefunction methods fail to adequately consider it. We introduce the Spin-Adapted Antisymmetrization Method (SAAM), a general procedure that enforces…

Chemical Physics · Physics 2025-11-04 Ruichen Li , Yuzhi Liu , Du Jiang , Yixiao Chen , Xuelan Wen , Wenrui Li , Di He , Liwei Wang , Ji Chen , Weiluo Ren

The Kittel--Shore Hamiltonian characterizes $N$ spins with identical long-range interactions, and the $\mathfrak{su}(2)$ coalgebra has been proven to be a symmetry of this model, which can be exactly solved. By using quantum groups and, in…

Statistical Mechanics · Physics 2025-12-18 V. Mariscal , J. J. Relancio

System consisting of a number of trapped atoms evolving under the influence of external inhomogenous magnetic field undergoes spin dephasing: classically, since each atom feels different field along its trajectory, the spin rotation rates…

Quantum Physics · Physics 2020-02-05 Konrad Szymański , Krzysztof Pawłowski

It is shown how quantum field theory at finite temperature can be used to set up self-consistent and gauge invariant equations for cosmological perturbations sustained by an ultrarelativistic plasma. While in the collisionless case, the…

General Relativity and Quantum Cosmology · Physics 2016-08-31 Anton K. Rebhan

Loop quantum cosmology is a symmetry-reduced application of loop quantum gravity that has led to the resolution of classical singularities such as the big bang, and those at the center of black holes. This can be seen through numerical…

General Relativity and Quantum Cosmology · Physics 2020-01-08 Alec Yonika , Gaurav Khanna

We establish an efficient approximation algorithm for the partition functions of a class of quantum spin systems at low temperature, which can be viewed as stable quantum perturbations of classical spin systems. Our algorithm is based on…

Quantum Physics · Physics 2023-10-25 Tyler Helmuth , Ryan L. Mann

We found the deviation of the equation of state from ultrarelativistic one due to quantum corrections for a nonequilibrium longitudinally expanding scalar field. Relaxation of highly excited quantum field is usually described in terms of…

High Energy Physics - Phenomenology · Physics 2019-02-20 A. V. Leonidov , A. A. Radovskaya

Inspired by path integral molecular dynamics, we build a spin model, in terms of spin coherent states, from which we can compute the quantum expectation values of a spin in a constant magnetic field, at finite temperature. This formulation…

Materials Science · Physics 2023-11-02 Thomas Nussle , Stam Nicolis , Joseph Barker

We simulate the dynamical spin structure factor (DSSF) $\mathcal{S}({q},\omega)$ of the spin-1/2 Heisenberg antiferromagnetic chain using classical simulations. By employing Landau-Lifshitz Dynamics, we emulate quantum correlations through…

Strongly Correlated Electrons · Physics 2026-01-15 Chaebin Kim , Martin Mourigal