QED auf dem Chip: Wechselwirkung von Quantenpunkten mit einem supraleitenden Resonator

A single quantum dot system used in our measurements. The right panel shows part of the electrical characterization ('charge stability diagram'). Excited states are clearly visible.

Quantum dot-resonator circuit. A spin qubit formed in a double quantum dot, each dot containing one electron, is placed at a maximum of the electric field inside a superconducting transmission line resonator. The resonator electric field couples to the interdot tunnel gate T, which modifies the tunnel barrier height. The electrons in the dots experience a magnetic field given by an applied field B_ext and Overhauser fields B_NL/NR due to nuclear spins, which are different for the two dots. The transmission line provides the coupling to a second spin qubit indicated on the left.