Andrew Eddins '11 from the Department of Physics at the University of California, Berkeley, will discuss "Superconducting Circuits for Quantum Metrology with Squeezed Microwaves."
Abstract: Intensive development of superconducting circuits has been driven by the prospect of quantum-computing applications. While most agree that practical quantum computers remain many years away, the interim development of quantum circuits opens previously inaccessible classes of quantum-physics experiments. For example, circuits have recently emerged as a powerful platform for studying the interaction of matter with a distinctly quantum type of radiation known as “squeezed” radiation, famous for enabling precision beyond the limit set by intrinsic quantum uncertainty, yet notoriously difficult to couple to in conventional AMO setups using lasers and atoms. In this talk, I will present a brief introduction to superconducting circuits, then discuss two experiments leveraging the circuit environment’s compatibility with squeezing, first studying how squeezing modifies fluorescence spectra of an atomic system, and second investigating the use of squeezing for the readout of a quantum-bit, the building block of proposed quantum computers. The results include the first confirmation of two nearly three-decade-old predictions of quantum optics, and the first demonstration that squeezed microwaves can improve the signal-to-noise ratio of quantum-bit readout."