Defence of doctoral thesis in the field of engineering physics, M.Sc. Bayan Karimi

In this thesis, we investigate both experimentally and theoretically phenomena and devices in quantum thermodynamics realized by superconducting and metal circuits on a chip at low millikelvin temperatures. This is a novel research area, coined circuit quantum thermodynamics, cQTD.

There are two central topics on which we present new results. The first one is the utilization of photonic heat transport on a chip. We develop theoretical models for a quantum Otto refrigerator and later for a transmon qubit-based quantum heat valve and rectifier that were realized experimentally in our laboratory during the course of this thesis. Experimentally we present an ultra-sensitive thermal detector reaching the ultimate noise level dictated by the fundamental thermal fluctuations. This allows us to consider the scheme of detecting single microwave photons in a continuous manner, calorimetrically. As a final boost to enhance the signal-to-noise ratio, we propose splitting of the photon to two uncorrelated baths and performing a cross-correlation measurement of their temperatures.

Opponents are Professor Michael Roukes, California Institute of Technology, USA and Doctor Rafael Sanchez, Universidad Autónoma de Madrid, Spain

Custos is Professor Jukka Pekola, Aalto University School of Science, Department of Applied Physics

Contact details of the doctoral student: [email protected] / [email protected]

The public defence will be organised in Otaniemi and via remote technology (Zoom). Zoom link

The dissertation is publicly displayed 10 days before the defence in the publication archive Aaltodoc of Aalto University

Electronic thesis