Kota L. Watanabe | Searcharxiv

arXiv2017

Geometric Fluctuation Theorem

We derive an extended fluctuation theorem for a geometric pumping in a spin-boson system under a periodic control of environmental temperatures by using a Markovian quantum master equation. We perform the Monte-Carlo simulation and obtain the current distribution, the average current and the fluctuation. Using the extended fluctuation theorem we try to explain the results of our simulation. The fluctuation theorem leads to the fluctuation dissipation relations but the absence of the conventional reciprocal relation.

cond-mat.stat-mech↗

arXiv2014

Non-adiabatic effect in quantum pumping for a spin-boson system

We clarify the role of non-adiabatic effects in a quantum pumping for a spin-boson system. When we sinusoidally control the temperatures of two reservoirs with π/2 phase difference, we find that the pumping current strongly depends on the initial condition, and thus, the current deviates from that predicted by the adiabatic treatment. We also analytically obtain the contribution of non-adiabatic effects in the pumping current proportional to Ω^3 where Ωis the angular frequency of the temperature control. The validity of the analytic expression is verified by our numerical calculation. Moreover, we extend the steady heat fluctuation theorem to the case for slowly modulated temperatures and large transferred energies.

cond-mat.stat-mech↗