Monitored quantum jumps: The view from quantum trajectory theory

Presenting Author: Howard Carmichael, University of Auckland

Quantum jumps are emblematic of all things quantum. Certainly that is so in the popular mind…and more than just an echo from the past, the term “quantum jump” still holds a prominent position within the lexicon of modern physics. What, however, is the character of the jump on close inspection? Is it discontinuous and discrete, as in Bohr’s original conception? Or is it some form of continuous Schrödinger evolution that might be monitored and reconstructed, even interrupted and turned around? I consider the jumps of single trapped ions observed in the mid-1980s [1], where an understanding drawn from quantum trajectory theory favours the latter option. I present that understanding and its connection to the modern view of continuous quantum measurement, and support this view from the theory side with experimental results [2], which recover the continuous and deterministic path of quantum jumps in a superconducting circuit using conditional quantum state tomography. [1] W. Nagourney et al., Phys. Rev. Lett. 56, 2797 (1986); T. Sauter et al., Phys. Rev. Lett. 57, 1696 (1986); J. C. Bergquist et al., Phys. Rev. Lett. 57, 1699 (1986). [2] Z. K. Minev, S. O. Mundhada, S. Shankar, P. Rheinhold, R. Gutiérrez-Jáuregui, R. J. Schoelkopf, M. Mirrahimi, H. J. Carmichael, and M. H. Devoret, arXiv:1803.00545 (2018).

(Session 7 : Monday from 10:45am - 11:30am)


SQuInT Chief Organizer
Akimasa Miyake, Associate Professor

SQuInT Local Organizers
Rafael Alexander, Postdoctoral Fellow
Chris Jackson, Postdoctoral Fellow

SQuInT Administrator
Gloria Cordova
505 277-1850

SQuInT Assistant
Wendy Jay

SQuInT Founder
Ivan Deutsch, Regents' Professor, CQuIC Director

Tweet About SQuInT 2019!