Energy conductance across a mesoscopic junction in a nonequilibrium spin-boson model under the influence of telegraph noise.

A spin-boson model in the presence of a telegraph noise (TN) source is employed to calculate the energy conductance between a tunnel junction and two bosonic baths. A polaron-transformed coupling term with the bosonic baths allows for treating quantum damping to arbitrary orders of strength. However, the polaron transformation yields a dressed tunneling frequency which is assumed small and treated perturbatively as is familiar in the noninteracting blip approximation in the context of the nonequilibrium spin-boson model.

Planar Hall effect and anisotropic magnetoresistance in polar-polar interface of LaVO-KTaO with strong spin-orbit coupling.

Among the perovskite oxide family, KTaO (KTO) has recently attracted considerable interest as a possible system for the realization of the Rashba effect. In this work, we report a novel conducting interface by placing KTO with another insulator, LaVO (LVO) and report planar Hall effect (PHE) and anisotropic magnetoresistance (AMR) measurements. This interface exhibits a signature of strong spin-orbit coupling.

Generalized fluctuation theorems for classical systems.

The fluctuation theorem has a very special place in the study of nonequilibrium dynamics of physical systems. The form in which it is used most extensively is the Gallavoti-Cohen fluctuation theorem which is in terms of the distribution of the work p(W)/p(-W)=exp(αW). We derive the general form of the fluctuation theorems for an arbitrary multidimensional Gaussian Markov process.

Glucose induced fractal colony pattern of Bacillus thuringiensis.

Growing colonies of bacteria on the surface of thin agar plates exhibit fractal patterns as a result of nonlinear response to environmental conditions, such as nutrients, solidity of the agar medium and temperature. Here, we examine the effect of glucose on pattern formation by growing colonies of Bacillus thuringiensis isolate KPWP1. We also present the theoretical modeling of the colony growth of KPWP1 and the associated spatio-temporal patterns.

Role of quantum heat bath and confinement in the low-temperature thermodynamics of cyclotron motion.

In this Brief Report we show how the low-temperature thermodynamics of the dissipative motion of an electron in a magnetic field is sensitive to the nature of the spectral density function, J(omega), of the quantum heat bath. In all cases of couplings considered here the free energy and the entropy of the cyclotron motion of the electron fall off to zero as power law in conformity with the third law of thermodynamics. The power of the power law however depends on the nature of J(omega).

Low-temperature thermodynamics in the context of dissipative diamagnetism.

We revisit here the effect of quantum dissipation on the much studied problem of Landau diamagnetism and analyze the results in the light of the third law of thermodynamics. The case of an additional parabolic potential is separately assessed. We find that dissipation arising from strong coupling of the system to its environment qualitatively alters the low-temperature thermodynamic attributes such as the entropy and the specific heat.

Diffusion enhancement in a periodic potential under high-frequency space-dependent forcing.

We study the long-time behavior of an underdamped Brownian particle moving through a viscous medium and in a systematic potential, when it is subjected to a space-dependent high-frequency periodic force. When the frequency is very large, much larger than all other relevant system-frequencies, there is a Kapitsa time window wherein the effect of frequency-dependent forcing can be replaced by a static effective potential. Our analysis includes the case in which the forcing, in addition to being frequency-dependent, is space-dependent as well.