We use nanolithography to create electronic devices, and measure their properties at ultralow temperatures, inside of a dilution refrigerator. Our measurement methods span audio, radio, and microwave frequencies, and often leverage techniques developed by the quantum-information-processing community.

Right now, we are interested in exploring new ways of coupling the motion of a tiny silicon nitride membrane to an electrical circuit. In previous work this system was used to make the world’s most efficient microwave-to-optical converter. Now, we are interested in using these membranes to sense the collective behavior of large arrays of Josephson junctions, giving us a new window into dynamical properties of their quantum phases.
Flip-chip image credit: Reed Andrews, JILA

We are also setting up an experiment aimed at performing low-noise measurements of the microwave properties of superconductor/semiconductor heterostructures. The aim of this direction will be to uncover fundamental information on how electricity flows when both a superconductor and semiconductor are present, which is an important pre-requisite for gate-based quantum electronics and topological superconductivity.