English
Related papers

Related papers: Negative Temperature in Spin Dynamics Simulations

200 papers

The dynamics of spin-boson systems at very low temperatures has been studied using a real-time path-integral simulation technique which combines a stochastic Monte Carlo sampling over the quantum fluctuations with an exact treatment of the…

chem-ph · Physics 2009-10-22 Reinhold Egger , C. H. Mak

A major goal of ultracold atomic physics is quantum simulation of spin Hamiltonians in optical lattices. Progress towards this goal requires the attainment of extremely low temperatures. Here we demonstrate a new cooling method which…

Theoretical and experimental studies of the interaction between spins and temperature are vital for the development of spin caloritronics, as they dictate the design of future devices. In this work, we propose a two-terminal cold-atom…

Quantum Gases · Physics 2021-12-09 R. E. Barfknecht , A. Foerster , N. T. Zinner , A. G. Volosniev

We present a method for performing atomistic spin dynamic simulations. A comprehensive summary of all pertinent details for performing the simulations such as equations of motions, models for including temperature, methods of extracting…

Materials Science · Physics 2014-04-04 B. Skubic , J. Hellsvik , L. Nordström , O. Eriksson

Spin-transfer is a typical spintronics effect that allows a ferromagnetic layer to be switched by spin-injection. Most of the experimental results about spin transfer are described on the basis of the Landau-Lifshitz-Gilbert equation of the…

Materials Science · Physics 2015-06-25 J. -E. Wegrowe , C. Ciornei , H. -J. Drouhin

A considerable body of experimental and theoretical work claims the existence of negative absolute temperatures in spin systems and ultra-cold quantum gases. Here, we clarify that such findings can be attributed to the use of a popular yet…

Statistical Mechanics · Physics 2015-06-15 Jörn Dunkel , Stefan Hilbert

We develop a novel approach to phase transitions in quantum spin models based on a relation to their classical counterparts. Explicitly, we show that whenever chessboard estimates can be used to prove a phase transition in the classical…

Mathematical Physics · Physics 2011-11-10 Marek Biskup , Lincoln Chayes , Shannon Starr

This paper aims to address the low-temperature dynamics issue for the $p=2$ spin dynamics with confining potential, focusing especially on quartic and sextic cases. The dynamics are described by a Langevin equation for a real vector $q_i$…

High Energy Physics - Theory · Physics 2024-09-17 Vincent Lahoche , Dine Ousmane Samary

An isolated spin system that is in internal thermodynamic equilibrium and that has an upper limit to its allowed energy states can possess a negative temperature. We calculate the thermodynamic characteristics and the concurrence in this…

Quantum Physics · Physics 2015-06-15 G. B. Furman , V. M. Meerovich , V. L. Sokolovsky

Atomistic spin dynamics (ASD) is a standard tool to model the magnetization dynamics of a variety of materials. The fundamental dynamical model underlying ASD is entirely classical. In this paper, we present two approaches to effectively…

Materials Science · Physics 2024-07-01 Marco Berritta , Stefano Scali , Federico Cerisola , Janet Anders

A well-established numerical technique to study the dynamics of spin systems in which symmetries and conservation laws play an important role is to microcanonically integrate their reversible equations of motion, obtaining thermalization…

Statistical Mechanics · Physics 2023-06-27 Andrea Cavagna , Javier Cristín , Irene Giardina , Mario Veca

We develop a method of non-perturbative optical control over adiabatic remagnetisation of the nuclear spin system and apply it to verify the spin temperature concept in GaAs microcavities. The nuclear spin system is shown to exactly follow…

Ultracold fermionic atoms in optical lattices offer pristine realizations of Hubbard models, which are fundamental to modern condensed matter physics. Despite significant advancements, the accessible temperatures in these optical lattice…

We review the non-zero temperature relaxational dynamics of quantum systems near a zero temperature, second-order phase transition. We begin with the quantum Ising chain, for which universal and exact results for the relaxation rates can be…

Strongly Correlated Electrons · Physics 2017-08-23 Subir Sachdev

We investigate the spin-squeezing behavior under thermal effects in a one-dimensional transverse field XY model with spin-1/2. The exact solution of the model helps us to compute the spin-squeezing parameter as a function of temperature and…

Quantum Physics · Physics 2024-12-09 Saeed Mahdavifar , Hadi Cheraghi , Kourosh Afrousheh

The physics of interacting nuclear spins arranged in a crystalline lattice is typically described using a thermodynamic framework: a variety of experimental studies in bulk solid-state systems have proven the concept of a spin temperature…

Mesoscale and Nanoscale Physics · Physics 2009-07-21 P. Maletinsky , M. Kroner , A. Imamoglu

An exact reduced dynamical map along with its operator sum representation is derived for a central spin interacting with a thermal spin environment. The dynamics of the central spin shows high sustainability of quantum traits such as…

Quantum Physics · Physics 2017-11-23 Chiranjib Mukhopadhyay , Samyadeb Bhattacharya , Avijit Misra , Arun Kumar Pati

We propose a systematic way to investigate the low-temperature thermodynamic properties of quantum spin systems subject to the restriction that only a finite number of bosons may occupy a single lattice site. Such a kinematical interaction…

Soft Condensed Matter · Physics 2016-08-31 L. V. Popovich , M. V. Medvedev

An important process for antimatter experiments is the cooling of particles in a Penning-Malmberg trap to experimentally useful temperatures. A non-neutral plasma of one species (e.g. antiprotons) can be collisionally cooled on another…

Plasma Physics · Physics 2025-11-13 James C. Welch , Louis Jose , Timothy D. Tharp , Scott D. Baalrud

Absolute temperature, the fundamental temperature scale in thermodynamics, is usually bound to be positive. Under special conditions, however, negative temperatures - where high-energy states are more occupied than low-energy states - are…

‹ Prev 1 2 3 10 Next ›