Related papers: Relaxation to Negative Temperatures in Double Doma…

Spin relaxation in a strong-coupling regime (with respect to the spin system) is investigated in detail based on the spin-boson model in a stochastic limit. We find a bifurcation phenomenon in temperature dependence of relaxation constants,…

Motivated by the recent experimental observation of negative absolute temperature states in systems of ultracold atomic gases in optical lattices [Braun et al., Science 339, 52 (2013)], we investigate theoretically the formation of these…

Driving an open spin system by two strong, nearly degenerate fields enables addressing populations of individual spin states, characterisation of their interaction with thermal bath, and measurements of their relaxation/decoherence rates.…

We revisit the dissipative approach to producing and stabilizing spin-squeezed states of an ensemble of $N$ two-level systems, providing a detailed analysis of two surprising yet generic features of such protocols. The first is a…

This article presents a dissipative method of creating a spin steady state, or a state whose spin expectation values approaches a fixed value over time, using a trapped gas of ultracold atoms coupled to a background BEC. The ultracold atoms…

Spontaneous nuclear polarization is predicted in double quantum dots in the spin-blocked electron transport regime. The polarization results from an instability of the zero-polarization state when singlet and triplet electron energy levels…

We consider a spin-$j$ particle coupled to a structured bath of bosonic modes that decay into thermal baths. We obtain an analytic expression for the reduced spin state and use it to investigate non-Markovian spin dynamics. In the heavily…

We investigate the dynamics of a 2-level atom (or spin-1/2) coupled to a mass-less bosonic field at positive temperature. We prove that, at small coupling, the combined quantum system approaches thermal equilibrium. Moreover we establish…

Redfield master equation was applied to study the dynamics of an ensemble of interacting pairs of unlike spins at room temperature. This spin quantum system is a workbench quantum model to analyze the relaxation dynamics of a heteronuclear…

We explore the dynamics of $N$ coupled atoms to a generic bosonic reservoir under specific system symmetries. In the regime of multiple atoms coupled to a single reservoir with identical couplings, we identify remarkable effects, notably…

The dynamics of open quantum systems connected with several reservoirs attract great attention due to its importance in quantum optics, biology, quantum thermodynamics, transport phenomena, etc. In many problems, the Born approximation is…

Physical systems reach thermal equilibrium through energy exchange with their environment, and for spins in solids the relevant environment is almost always the host lattice in which they sit. However, recent studies motivated by…

Complex environments, such as molecular matrices and biological material, play a fundamental role in many important dynamic processes in condensed phases. Because it is extremely difficult to conduct full quantum dynamics simulations on…

A robust scheme for state preparation and state trapping for the spins of two electrons in a semiconductor double quantum dot is presented. The system is modeled by two spins coupled to two independent bosonic reservoirs. Decoherence…

We study the spin--boson model with a sub--Ohmic bath using infinitesimal unitary transformations. Contrary to some results reported in the literature we find a zero temperature transition from an untrapped state for small coupling to a…

We study the thermodynamic properties of cold spin-1 atoms with a fixed magnetization M and decoupled from spatial modes. Three temperature domains are found: (0, T1) is a domain of second condensation, namely, both the spatial and spin…

We study the stationary nonequilibrium regime which settles in when two single-spin paramagnets each in contact with its own thermal bath are coupled. The response vs. correlation plot exhibits some features of aging systems, in particular…

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…

Spin relaxation is investigated theoretically in two-dimensional systems. Various semiconductor structures of both n- and p-types are studied in detail. The most important spin relaxation mechanisms are considered. The spin relaxation times…

We derive a simple system of equations to describe the magnetization relaxation of a molecular spin in weak interaction with a thermal bath for the whole temperature domain. Using this for the intermediate temperature domain where the…