Regensburg 2019 – wissenschaftliches Programm
TT 10.1: Hauptvortrag
Montag, 1. April 2019, 15:00–15:30, H2
Quantum dynamics of a microwave resonator strongly coupled to a tunnel junction — •Jérôme Esteve — Laboratoire de Physique des Solides, CNRS, Université Paris-Sud, Université Paris-Saclay, Orsay, France
The coupling of a quantum system, such as an atom or a resonator, to a bath can be modeled under certain hypotheses by a quantum master equation in the Lindblad form. In this description, two effects arise from the coupling to the bath: the first is a shift of the energy levels, called Lamb shift, and the second is an irreversible energy exchange with the bath in the form of quantum jumps.
A tunnel junction galvanically coupled to a resonator realizes a bath for the resonator mode. In the strong coupling regime, where the characteristic impedance Zc of the resonator is on the order of the quantum of resistance RK = h/e2, we will show that both the Lamb shift and the jump operators strongly depend on the resonator state. Different Fock states experience different Lamb shifts, which introduces a non-linearity, and quantum jumps from a specific Fock state to another can be forbidden by tuning the coupling parameter √π Zc/RK to specific values.
We will discuss the dynamics of the resonator mode resulting from this engineered bath and consider possible applications including quantum Zeno dynamics and the realization of a qubit without Josephson effect.