Seminar on July 18, 2019 at 3:30 PM

Date: 
Thu, 07/18/2019 - 3:30pm
Location: 
705 Pupin

Speaker: R. Gutierrez-Jauregui, Institute for Quantum Science and Engineering, Texas A&M University

Title: "To catch a quantum jump mid-flight: a quantum trajectory perspective"

Abstract: Quantum jumps of single trapped ions were observed in the seminal experiments of Dehmelt, Wineland, and Toschek groups in the mid 1980's. The idea behind these experiments was seeded in Dehmelt's electron shelving configuration, where the fluorescence of a driven two-state system is abruptly interrupted as the system transitions to a third, metastable, state. In this sense the transition to the metastable state is inferred from the lack of fluorescence photons, a sequence of ``nothing-happened" or null measurements. Null-measurement is a cornerstone of quantum trajectory theory, a theory we apply to model the electron shelving experiment and show that the transition is described by a coherent continuous evolution. The theoretical result is supported by a recent experiment using a superconducting circuit architecture where these transitions are caught mid-flight, thus showing the coherent evolution in striking fashion.

In this talk, I review Dehmelt's original proposal from a quantum trajectory perspective before I move towards an analysis of the model recently presented using a circuit QED architecture.