Bayan Karimi - ESR 4, January 2018 - December 2020
Department of Applied Physics, Aalto University, Helsinki, Finland
Master thesis: “Preparation of copper nitride thin films by reactive magnetron sputtering and investigation of their electrical and optical characteristics by varying deposition conditions”, Supervisor: Prof. H. Bidadi, University of Tabriz, Iran
Personal Training Committee
Main Supervisor: Jukka Pekola AALTO
Co-supervisor: Hervé Courtois, CNRS
Mentor: Arttu Luukanen, Asqella Oy
At CHALMERS (March 2019) to get trained on superconducting resonators,
At RAITH (November 2019, March 2020) to learn EBL-based nanofabrication,
At UKON (remotely, Fall 2020) to look at the influence of non-equilibrium energy distributions on the thermometer measurements
Quantum thermodynamics by nanocalorimetry
Objectives: The project focuses on the measurement of microwave photons emitted by superconducting quantum circuits. The task is to develop a nanocalorimeter, which is capable of measuring subkelvin energy quanta with microsecond time resolution. The noise-equivalent temperature that can be reached is in few µK/Hz1/2 range, limited by fundamental energy fluctuations. The measurement requires RF-detection with a temperature sensitive element coupled to a very low heat capacity absorber thus providing a wide-band detector. An immediate choice is a hybrid NIS tunnel junction as a thermometer and a nanofabricated metallic or semiconducting absorber.
We will analyse such a calorimeter theoretically, optimise its parameters and materials and implement it in a low temperature set-up (dilution refrigerator). The calorimeter will be tested (i) by applying external Joule-heating and measuring thermal relaxation time and heat capacity of the absorber, (ii) by injecting hot-electron excitations of energy D from superconducting aluminium, and by measuring these “quanta” calorimetrically, and finally (iii) by combining the calorimeter with a superconducting quantum bit acting as a single-photon source.