AQP Seminar: Extracting temperatures of the leads in non-equilibrium transport setups

Aalto Quantum Physics Seminar (Nanotalo). Speaker: Dr. N. Lo Gullo (University of Turku)

The measurement of temperatures in transport setups is of crucial importance in the study of thermodynamic properties of quantum systems. From temperatures one can derive key quantities such as efficiency of a thermal machine, Seebeck coefficient, heat currents to mention a few.
From the experimental side there have been impressive progresses in measuring the temperature and even its fluctuations in time, whereas the approach to compute the temperature mostly relies on phenomenological balance equations. The latter have proven to work really well, but they hide the microscopic origin of the change of temperatures.

In my talk I will present a microscopic theory based on non-equilibrium Green’s functions to extract the temperatures of the leads. I will first show the main physical idea behind it and how it is translated into the formalism. I will then give two examples where our approach can be applied and discuss the validity of our results from the thermodynamical viewpoint.