CMSP Seminar Series @ICTP Stasi Seminar Rm. Thursday 8 March 11am - A.ROSCH

[CM Section]

ICTP Seminar Series in Condensed Matter and Statistical Physics
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Thursday 8 Marchat 11:00 a.m.

Luigi Stasi Seminar Room, first floor, ICTP Leonardo building
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Speaker:
Achim ROSCH (University of Cologne, Germany)

Title:
Pumping Spin-Chain Materials and the Emergence of
Generalized Gibbs Ensembles

Abstract:

Weak perturbations can drive an interacting many-particle system
far from its initial equilibrium state if one is able to pump into degrees
of freedom approximately protected by conservation laws. We develop
a theory of weakly driven integrable systems and show that pumping
can induce large spin or heat currents even in the presence of integrability
breaking perturbations, since it activates local and quasi-local approximate
conserved quantities. The resulting steady state is qualitatively 
captured by
a generalized Gibbs ensemble with Lagrange parameters that depend on
the structure but not on the overall amplitude of perturbations nor the 
initial
state. We suggest to use spin-chain materials driven by terahertz radiation
to realize integrability-based spin and heat pumps. We also show that time-
dependent generalized Gibbs ensembles accurately describe the time
evolution of weakly driven, approximately integrable systems.