Stirring by Staring

TYPECondensed Matter Seminar
Speaker:Israel Klich
Affiliation:University of Virginia
Organizer:Ari Turner
Date:28.06.2022
Time:14:30 - 15:30
Location:Lidow Nathan Rosen (300)
Abstract:

In quantum mechanics, the role of an observer is fundamentally different from that of a classical observer.  The quantum mechanical observer necessarily plays an active role in the dynamics of the system that it is observing.  This apparent difficulty may be turned into a tool to drive an initially trivial system into a complicated quantum many-body state simply by observing it.  I will present two remarkable examples of states induced by measurement. In the first, we examine the role of a moving density measuring device interacting with a system of fermions, and in particular, show that it would leave behind a wake of purely quantum origin. In the second example, inspired by topological Floquet insulators, we will see how a suitably chosen set of density measurements, repeated periodically, will induce robust chiral edge motion of fermions. These examples show how quantum mechanical observation can be added as a versatile tool to the arsenal of quantum engineering in condensed matter systems.