Seminar by Klaus Ensslin

Friday 12 October 2018 14:00 - 15:00
Published 2018-07-03 03:33 by Heiner Linke

Seminar by Klaus Ensslin, Artis Svilans' opponent:

Strong coupling of microwave photons to spin and charge qubits

The strong coupling between a microwave resonator and a semiconductor quantum system is enabled by a high impedance resonator, a careful gate design, and an optimized qubit configuration. Here we focus on spin and charge qubits in GaAs quantum dots which serve as a model system since their fabrication is mature and reliable and the basic decoherence mechanisms are known. We demonstrate strong coupling between photons in a SQUID-array resonator and a charge qubit realized in a double dot. In another experiment a triple dot is tuned to the regime of the resonant exchange qubit and is strongly coupled to a NbTiN strip-line resonator. Here it is the spin distribution in the triple dot that creates the qubit rather than the absolute value of the spin. We discuss the prospects of different material systems and show in particular that graphene and TMDCs offer unique opportunities for spin physics in the absence or presence of spin-orbit interactions.