3 seminars next week held at SISSA

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

JOINT ICTP/SISSA STATISTICAL PHYSICS SEMINAR

 

Tuesday, 27 January  -   11:00 a.m.

 

SISSA, Santorio Building,    Room 128 (First floor)

 

 

Nuria BARBERAN    ( Universitat de Barcelona )

  

"Simulation of the fractional quantum Hall effect"

 

 Abstract

We perform an analysis of the role played by impurities in the fractional quantum Hall effect, that is, the mechanism that causes, in the lowest Landau level regime, the formation of plateaux in the resistivity as a function of the magnetic applied field. To this end within the framework of quantum simulation, we consider an impurity immersed in a small ultracold quantum bosonic gas trapped in a rapidly rotating potential (which generates an artificial magnetic field), an experimentally realistic system adequate to realize quantum Hall effects. We use exact diagonalization for few atoms and apply the linear response theory to simulate the transport equation. We provide a proposal of a theoretical technique to detect the up-to-now elusive presence of strongly correlated states related to fractional filling factors in the context of ultracold atoms. We analyse for the first time, the conditions under which these strongly correlated states are associated to the presence of the plateaux.

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JOINT ICTP/SISSA STATISTICAL PHYSICS SEMINAR

 

Thursday, 29 January   -   2:00 p.m.

 

 

SISSA, Santorio Building,  Room 005 (Ground floor)

 



Michele CAMPISI   ( Scuola Normale Superiore, Pisa )

 

"Nonequilibrium fluctuations in quantum heat engines:  Theory, example, and possible solid state experiments"



Abstract

We study the stochastic energetic exchanges in quantum heat engines.  Due to microreversibility, these obey a fluctuation relation, called the heat engine fluctuation relation, which implies the Carnot bound: no machine can have an efficiency larger than Carnot's efficiency. The stochastic thermodynamics of a quantum heat engine (including the joint statistics of heat and work and the statistics of efficiency) is illustrated by means of an optimal two-qubit heat engine, where each qubit is coupled to a thermal bath and a two-qubit gate determines energy exchanges between the two qubits. We discuss possible solid state implementations with Cooper pair boxes and flux qubits, quantum gate operations, and fast calorimetric on-chip measurements of single stochastic events.

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JOINT ICTP/SISSA STATISTICAL PHYSICS SEMINAR

 



Friday, 30 January   -   2:00 p.m.

 



SISSA, Santorio Building,   Room 005 (Ground floor)

 



Gabor TAKACS     ( Budapest University of Technology and Economics )



"Form factor relocalisation and interpolating renormalisation group flows from the staircase model"



Abstract

 

We investigate the staircase model, introduced by Aliosha Zamolodchikov through an analytic continuation of the sinh-Gordon S-matrix to describe interpolating flows between minimal models of conformal field theory in two dimensions. Applying the form factor expansion and the c-theorem, we show that the resulting c-function has the same physical content as that found by Zamolodchikov from the thermodynamic Bethe Ansatz. This turns out to be a consequence of a nontrivial underlying mechanism, which leads to an interesting localisation pattern for the spectral integrals giving the multi-particle contributions. We demonstrate several aspects of this form factor relocalisation, which suggests a novel approach to the construction of form factors and spectral sums in integrable renormalisation group flows with non-diagonal scattering.