SCHOOL OF NANO SCIENCE

Monthly Colloquium

Measurement protocols for many-body observables in synthetic quantum matters

Abstract:

We discuss two specific cases of characterization and measurement techniques for many-body quantum systems. (1) Entanglement plays a major role in characterizing many-body quantum systems. In particular, the entanglement spectrum holds a great promise to characterize essential physics of quantum many-body systems. While there has been a surge of theoretical works on the subject, no experimental measurement has been performed to this date, due to the lack of an implementable measurement scheme. We propose a measurement protocol to access the entanglement spectrum of many-body states in experiments with cold atoms in optical lattices. (2) There has been recent progress in understanding chaotic features in many-body quantum systems. Motivated by the scrambling of information in black holes, it has been suggested that the time dependence of out-of-time ordered (OTO) correlation functions is a faithful measure of quantum chaos. We propose a protocol to measure such OTO correlators using an ancilla which controls the direction of time and plays the role of a 'quantum clock' Our protocol is immune to errors that could occur when the direction of time evolution is externally controlled by a classical switch. In the end, I show one can use a similar cavity-QED architecture to perform a digital quantum simulation of fermionic models.

More Information

Seminar Speaker:
Dr. Mohammad Hafezi
Date :
16 Aug. 2017
Time :
16:00
Venue:
Farmaniyeh Building, Conference Hall