126 research outputs found
Stochastic Thermodynamics of oscillators networks
We apply the stochastic thermodynamics formalism to describe the dynamics of
systems of complex Langevin and Fokker-Planck equations. We provide in
particular a simple and general recipe to calculate thermodynamical currents,
dissipated and propagating heat for networks of nonlinear oscillators. By using
the Hodge decomposition of thermodynamical forces and fluxes, we derive a
formula for entropy production that generalises the notion of non-potential
forces and makes trans- parent the breaking of detailed balance and of time
reversal symmetry for states arbitrarily far from equilibrium. Our formalism is
then applied to describe the off-equilibrium thermodynamics of a few examples,
notably a continuum ferromagnet, a network of classical spin-oscillators and
the Frenkel-Kontorova model of nano friction.Comment: 8 pages, 1 figur
Spin relaxation signature of colossal magnetic anisotropy in platinum atomic chains
Recent experimental data demonstrate emerging magnetic order in platinum
atomically thin nanowires. Furthermore, an unusual form of magnetic anisotropy
-- colossal magnetic anisotropy (CMA) -- was earlier predicted to exist in
atomically thin platinum nanowires. Using spin dynamics simulations based on
first-principles calculations, we here explore the spin dynamics of atomically
thin platinum wires to reveal the spin relaxation signature of colossal
magnetic anisotropy, comparing it with other types of anisotropy such as
uniaxial magnetic anisotropy (UMA). We find that the CMA alters the spin
relaxation process distinctly and, most importantly, causes a large speed-up of
the magnetic relaxation compared to uniaxial magnetic anisotropy. The magnetic
behavior of the nanowire exhibiting CMA should be possible to identify
experimentally at the nanosecond time scale for temperatures below 5 K. This
time-scale is accessible in e.g., soft x-ray free electron laser experiments.Comment: 9 pages, 3 figure
- …