Strong Radiation-Matter Interaction in a Driven Superconducting Quantum System
Thesis event information
Date and time of the thesis defence
Place of the thesis defence
Linnanmaa, lecture room L7
Topic of the dissertation
Strong Radiation-Matter Interaction in a Driven Superconducting Quantum System
Doctoral candidate
Master of Science Iivari Pietikäinen
Faculty and unit
University of Oulu Graduate School, Faculty of Science, Nano and Molecular Systems Research Unit (NANOMO)
Subject of study
Theoretical physics
Opponent
Professor Zaki Leghtas, Mines ParisTech
Custos
Professor Erkki Thuneberg, University of Oulu
Strong radiation-matter interaction
In my thesis we studied strong interaction between radiation and matter in superconducting electric circuits. Typically this interaction is investigated in systems consisting of electric fields and single atoms. With the electric circuits one can accomplish stronger coupling between the radiation and matter.
This research was done with a system consisting of waveguide resonator coupled to a transmon qubit. Qubit is a quantum mechanical two-state system. The waveguide resonator was driven to higher energy state with a strong voltage. For weak driving the system behaves quantum mechanically and for strong driving classically. The research focused on the region between the quantum limit and the classical limit.
We showed that, as the system is driven from the quantum regime to the classical one, also the higher states of the transmon device are important. Also, we compared the Floquet-Born-Markov method that we used to a commonly used Linndbald master equation method. The results from both methods were very close but the Floquet-Born-Markov method was much faster.
This research was done with a system consisting of waveguide resonator coupled to a transmon qubit. Qubit is a quantum mechanical two-state system. The waveguide resonator was driven to higher energy state with a strong voltage. For weak driving the system behaves quantum mechanically and for strong driving classically. The research focused on the region between the quantum limit and the classical limit.
We showed that, as the system is driven from the quantum regime to the classical one, also the higher states of the transmon device are important. Also, we compared the Floquet-Born-Markov method that we used to a commonly used Linndbald master equation method. The results from both methods were very close but the Floquet-Born-Markov method was much faster.
Last updated: 1.3.2023