Princeton University

School of Engineering & Applied Science

Quantum Interference Effects in a 3D Transmon ^-System

Benjamin Palmer. University of Maryland
B205 Engineering Quadrangle
Wednesday, February 17, 2016 - 4:00pm to 5:00pm

A three level ^ system dressed by two coherent light fields can exhibit exotic quantum interference effects such as coherent population trapping (CPT) and electromagnetically induced transparency (EIT).  By addressing the combined qubit and cavity states of an Al/AlOx/Al transmon qubit in a 3D Cu cavity with two microwave drives, we have established an effective  ^-system, two legs of which are defined by a dipole transition and a two-photon transition. This configuration allows us to pump into a metastable state of the  ^ -system and use a three photon Raman process to generate CPT. We also find that the transmission through the cavity is electromagnetically suppressed, resulting in the superluminal propagation of Gaussian pulses with group velocities of -1.8 km/sec or advances of 9 microseconds.