Dipole coupling of a double quantum dot to a microwave resonator

We have realized a novel device in which a semiconductor double quantum dot is dipole coupled to a GHz-frequency high-quality transmission line resonator. This approach allows us to characterize the properties of the double dot by measuring both its dispersive and dissipative interaction with the resonator. In addition to providing a new readout mechanism, this architecture has the potential to isolate the dots from the environment and to provide long distance coupling between spatially separated dots. These features are expected to improve the potential for realizing a quantum information processor with quantum dots as previously demonstrated for superconducting circuits making use of circuit quantum electrodynamics.

Figure 1: (a) Optical micrograph of the microwave resonator (R), with integrated double quantum dot, Ohmic contacts (M), top gates (C), ground plane (GND), and on-chip inductor (I). Inset: Magnified view of inductor (I). (b) Enlarged view of the device near the double quantum dot. The mesa edge is highlighted with a dashed line. (c) Scanning electron micrograph of the gate structure defining the double quantum dot (LD, RD). (d) Electric circuit representation of the double quantum dot coupled to the resonator.

Full article:
http://prl.aps.org/abstract/PRL/v108/i4/e046807 or arXiv:1108.3578


T. Frey, P. J. Leek, M. Beck, J. Faist, A. Wallraff, K. Ensslin, T. Ihn, and M. Büttiker, Phys. Rev. B 86, 115303 (2012)