Effect of the measurement circuit on the fluctuation theorem for the electric current through a semiconducting nanostructure

点击翻译按钮获取中文摘要

The fluctuation theorem (FT) which is valid far from equilibrium and extends the second law of thermodynamics to small systems, has been recently applied to the mesoscopic quantum transport. We have theoretically studied the impact of the measurement circuit on the FT of quantum conductors. 1) We have considered the FT for a coupled system, an electron wave interferometer and an LC circuit (measurement circuit), and found that the back-action of the measurement circuit is necessary to be consistent with the FT for this setup. 2) We theoretically derived and experimentally checked universal relations among nonlinear 4-terminal transport coefficients of a coupled system, a double-quantum dot and a quantum point contact (measurement circuit). 3) We have also found a novel switching exponent for the magnetization reversal driven by the non-conservative spin torque and thermal fluctuations.