CMSP Seminar Series @ICTP Thursday 12 Jan. at 11:30 in L.Stasi Seminar Rm. - Alioscia HAMMA

[Condensed Matter Section]

ICTP Seminar Series in Condensed Matter & Statistical Physics
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Thursday 12 January at 11.30 a.m.
Luigi Stasi Seminar Room, first floor, ICTP Leonardo Building

Alioscia HAMMA
Dept. of Physics, Univ. of Massachusetts, Boston, USA

" Order, Equilibrium, Memory: The Search for a Quantum Hard Drive and New
Laws for Non Equilibrium Quantum Statistical Mechanics "

Abstract:
The three concepts of the title are closely related in statistical 
mechanics and condensed matter. Order is an organisational principle 
that gives a material its macroscopic properties.

Equilibration is the most common phenomenon in Nature. There is no other 
law that is stronger than the one that imposes systems to eventually 
reach equilibrium.

On the other hand, memory is the property of staying away from 
equilibrium. If one has to store information, one has to keep a system 
away from equilibrium for long times.

All these concepts can be illustrated by the functioning of a device 
that we use every day: the Hard Drive. In this talk, I will tackle the 
following question: can one build a Quantum Hard Drive?

In this talk, I show that the existence of exotic phases of the matter 
called topological phases - which do not rely on the symmetry breaking 
mechanism - provides a mechanism for keeping quantum states alive for a 
long time, and therefore to build a quantum hard drive. This kind of 
order relies on a topological pattern of entanglement. I will address 
the problem of the survival of Topological Order at finite temperature 
and after a quantum quench. Time permitting, I will discuss some novel 
routes towards a stable quantum memory, including many-body localization.