CMSP Section announces 4 seminars next week - Luigi Stasi Seminar Room

[Cond.Matt. & Stat.Mech.Section]

JOINT ICTP/SISSA STATISTICAL PHYSICS SEMINAR


Tuesday, 17 February  -   11:00 hrs.


Luigi Stasi Seminar Room -  ICTP Leonardo Building - 1st floor


Lapo CASETTI    (Università di Firenze)


"Temperature inversion in  long-range interacting systems"
 

Abstract

Temperature inversions occur in nature, e.g., in the solar corona and in interstellar molecular clouds: somewhat counterintuitively, denser parts of the system are colder than dilute ones. We try to understand which are the minimal ingredients and the basic physical mechanism behind such phenomena. We suggest that temperature inversions may spontaneously occur in a generic system with long-range interactions that is prepared in an inhomogeneous thermal equilibrium state and then brought out of equilibrium by applying an impulsive perturbation. In similar situations, short-range systems would typically relax to another thermal equilibrium, with uniform temperature profile. By contrast, in long-range systems, the interplay between wave-particle interaction and spatial inhomogeneity drives the system to nonequilibrium stationary states that generically exhibit nonuniform temperature profiles with temperature inversion. This shows how crucial the role played by the range of interparticle interactions is in determining the nature of steady states attained when macroscopic systems are brought out of thermal equilibrium.


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CONDENSED MATTER AND
STATISTICAL PHYSICS
SEMINAR
 

Wednesday, 18 February -    4:00 p.m.


Luigi Stasi Seminar Room -   ICTP Leonardo Building   (first floor)

 

Antonello SCARDICCHIO    ( ICTP )


"Local integrals of motion in the   many-body localized phase"


Abstract

Many-body localization is the suppression of transport in disordered, interacting systems. It is now clear that many realistic disordered spin and particle systems do possess such a phase and that this has profound implications for the system's dynamics. Recently, a characterization of the MBL phase has been proposed in terms of the existence of local integrals of motion. I will show how to build such local integrals of motion in perturbation theory in the interaction and how to find the phase boundaries.  If time allows, I will also comment on the implications of this work for the performance of the quantum adiabatic algorithm.

  Joint work with  M. Müller, V. Ros.

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SPECIAL SEMINAR
 

Thursday, 19 February -    10:00 a.m.


Luigi Stasi Seminar Room -   ICTP Leonardo Building   (first floor)


Francois HUVENEERS   ( CEREMADE, Université Paris-Dauphine)
 

"Many-body localized systems under driving"


Abstract

Isolated many-body quantum systems may fail to thermalize due to quantum interferences. This phenomenon has the same origin as Anderson localization and is referred to as many-body localization (MBL). In this talk, we will investigate how a localized system responds to an external time-dependent driving. In particular, we will ask whether the system absorbs energy until it reaches an infinite temperature state, as it would be the case for an ergodic system, or whether absorption eventually saturates.

Collaboration with D. Abanin, W. De Roeck, Z. Papic and P. Ponte.

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INFORMAL SEMINAR on Chemical Physics


Thursday, 19 February -    11:30 a.m. 

 
Luigi Stasi Seminar Room, ICTP Leonardo Building (1st floor)


Gabriele D'AVINO  (Laboratory for Chemistry of Novel Materials,   University of Mons, Belgium)


"Modelling charge transfer in molecular materials: from photovoltaics to ferroelectrics"



Abstract


Charge transfer (CT) interactions between electron donor (D) and acceptor (A) molecules are central to many physical phenomena in chemistry, biology and materials science. In this talk I will present some recent work on the modelling D/A interfaces for photovoltaic applications and mixed-stack CT crystals, for which we propose a multiscale modelling approach based on first-principles and model Hamiltonian electronic structure calculations, and classical schemes to account for electrostatic and polarization interactions at the mesoscale.