laboratoire pierre aigrain
électronique et photonique quantiques
 
laboratoire pierre aigrain
 

Seminaire, 13 Janvier 2014

J. Viennot (LPA, ENS)
Out of equilibrium charge dynamics in a cCQED architecture

In the context of circuit quantum electrodynamics, recent developments
made it possible to build hybrid circuits [1], including many types of
quantum dots. The versatility of these systems allows us to explore
several directions, from quantum information engineering to many-body
physics, all in a circuit QED architecture. I will present some of the
experiments of our group where a carbon nanotube-based double quantum dot is coupled to a microwave cavity. Using a novel carbon nanotube stamping technique [2], we demonstrate a strong electron confinement, allowing us to bring the system at resonance with the cavity and use it as a charge qubit. We characterise the response of this circuit out of equilibrium, driving the system either with a finite bias or with a microwave spectroscopic tone [3]. Combined with exchange Zeeman fields induced by ferromagnetic interfaces, such a control should enable us to go towards spin-photon coupling and spin qubit experiments for circuit QED [4]. I will discuss some preliminary results pointing towards spin-photon coupling signatures in such an architecture.

References :
[1] M.R. Delbecq et al. Nature Comm., 4, 1400 (2013).
[2] J.J. Viennot et al., in preparation.
[3] J.J. Viennot et al., arXiv:1310.4363.
[4] A. Cottet et al., Phys. Rev. Lett. 105, 160502 (2010).