For those of you who don’t know, SQuInT stands for “Southwest Quantum Information and Technology” and has been having a conference in the Southwest united states for seven years (and even longer if you count some “pre”-SQuInTs.) SQuInT is becoming more and more unique in that it is one of the rare conferences which tries to bring together the different parts of physics which are all involved in trying to build a quantum computer. They even have a few talks by silly theorists like me. My talk wasn’t as good as I had hoped. 30 minutes is pretty darn stringent.
The highlight of the conference, besides the night spent watching the old couples work the dance floor at the “exclusive” resort in Tuscon where the conference was held, was to hear about the work of Robert Schoelkopf from Yale on combining cavity quantum electrodynamics with superconducting qubits. Traditional cavity QED is done with cavities coupling to neutral atoms (in either a microwave or optical regime.) Some of the earliest quantum computing implementations were performed in cavity QED by Jeff Kimble’s lab at Caltech. What Robert talked about was using a cavity to couple to a hybrid superconducting qubit. He showed some really nice results demonstrating the vacuum Rabi oscillations from his coupling of the cavity to his superconducting qubit. An amazing aspect of this system is that the effective dipole moment of the superconducting qubit is about ten thousand times stronger than in neutral atoms. Why is this important for quantum computing? It’s probably most important because one of the most difficult tasks for many solid state quantum computing systems is the ability to perform readout of the state of the qubit with a high reliability and without destroying the system. Robert’s scheme shows a reasonable chance of performing such a task. For those of you who wish to bet with me on what the final quantum computer will look like, the SQuInT conference and Robert’s results in particular have made me recalculate my odds. Please send me an email if you would like to place a bet ; )