Coupling electrons on helium to a fast charge detector

The ability to measure a small fraction of an electron charge with high bandwidth (typically > 100 MHz) has made the radio-frequency Single Electron Transistors (rf-SET) a useful tool to study a variety of quantum devices including Cooper-pair boxes, quantum dots, and nanomechanical resonators. Here we present preliminary results on the coupling of quasi-1D electrons floating on the surface of liquid helium to an rf-SET device. In this device, a superconducting SET, located below the liquid helium, capacitively couples to the electron system on the surface of the liquid. Different spatial configurations of the electron system are controlled using gate electrodes and induce a characteristic charge offset on the SET island. Measuring the damping of microwaves from an on-chip LC-tank circuit connected to the SET device enables readout of fast charge dynamics in the electron system. We also investigate the high-frequency response of the surface state electrons at the phase transition between the electron liquid and Wigner solid states.