Kondo induced pi-phase shift of microwave photons in a circuit quantum electrodynamics architecture

Article

关键词: TRANSPORT;    DOT;    TOPOLOGY;    DYNAMICS;    GRAPHENE;    CHARGE;   

DOI  :  10.1103/PhysRevB.104.125407

来源: SCIE

【 摘 要 】

The Kondo effect refers to the screening of a spin-1/2 impurity by a cloud of conduction electrons, then forming a many-body Fermi liquid ground state. Theoretical calculations suggest that the Kondo resonance can interact with light and should give rise to a pi-phase shift of the photon signal in the case where the ground state is a Fermi liquid. This pi-phase shift of light is driven from the Korringa-Shiba relation of quantum impurity Fermi-liquid ground states. We report the first observation of such a pi-phase shift in a graphene double quantum dot within a circuit quantum electrodynamics architecture where themicrowave photons couple to the pseudospin or charge degrees of freedom. We study the evolution of the pi-phase shift as a function of temperature and bias voltage. The observed Kondo temperature T-K similar to 550 mK is in agreement with dc conductance measurements. All our results support the formation of a Kondo resonance located above the Fermi level of the electronic reservoirs with the occurrence of an SU(4) Fermi-liquid ground state. We finally study how the Kondo-photon interaction can be tuned by inter-dot electron tunnel coupling strengths. Our findings may contribute to a better understanding of many-body physics in hybrid circuit systems, and open up applications in atomic thin materials from the light-matter interaction.

【 授权许可】

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