The measurement phase transition

by Prof. Jonathan Ruhman

BIU

at Condensed Matter Seminar

Mon, 22 Nov 2021, 11:30
Sacta-Rashi Building for Physics (54), room 207

Abstract

The entanglement between different degrees of freedom in a closed many body system increases with time due to interaction. On the other hand local quantum measurements reduce the entanglement by projecting degrees of freedom to the measurement basis. Thus, one may wonder what is the fate of the entanglement in a system that is undergoing time evolution whilst being monitored. I will show that there exists a sharp dynamical phase transition controlled by the measurement rate between a disentangling phase, where entanglement of a subregion is only proportional to its area (area law) and an entangling phase where the entanglement is extensive. While this transition can only be conjectured in 1+1d models based on numerics, in all-to-all models, where all the degrees of freedom interact equally with all other degrees of freedom, exact results can be found substantiating the existence of this transition in quantum systems.

Created on 14-10-2021 by Meidan, Dganit (dganit)
Updaded on 18-11-2021 by Meidan, Dganit (dganit)