3 seminars coming up

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

SEMINAR on    Disorder and strong electron correlations

 

Thursday, 3 March -  11:30 a.m.



Luigi Stasi Seminar Room,  Leonardo Building - first floor

 

John T. CHALKER    ( University of Oxford )


 "Integer quantum Hall edge states  far from equilibrium"



 Abstract

 

A non-equilibrium distribution of electrons is set up when two quantum Hall edge states originating from sources at different potentials meet at a quantum point contact.  Recently, several types of experiment have probed the consequences of this non-equilibrium distribution, first in interferometers, and recently by a direct measurement of the distribution and its evolution with distance downstream from the quantum point contact [1].

In this talk I will describe theoretical work [2] aimed at understanding aspects of these experiments.

 References

[1] H. le Sueur, C. Altimiras, U. Gennser, A. Cavanna, D. Mailly, F. Pierre, Phys. Rev. Lett. 105, 056803 (2010).

[2] D. L. Kovrizhin and J. T. Chalker, arXiv:1009.4555, and in preparation.

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SPECIAL SEMINAR

Thursday, 3 March -    4:00 p.m.



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



Nicola SERIANI    (I.C.T.P.)

  

"Energy conversion and storage with nanomaterials: Atomistic simulations"

 

Abstract

 

The capability of materials for energy conversion and storage can be considerably extended by nanostructuring.  The morphology and stability of a nanostructure depend crucially on the environmental conditions of fabrication and operation.  It is therefore fundamental for energy applications to understand in detail how the environment influences these properties.  In this talk, I will discuss atomistic simulations based on density functional theory aimed at investigating the formation and stability of nanostructures of oxides of platinum-group metals and of lithium in an oxygen-rich environment.  These systems are relevant for fuel cells and lithium-air batteries, respectively.  I will show that the thermodynamics of oxides is different when the nanoscopic size is taken into account and that this has consequences for their functionality.  I will thoroughly compare the calculations with experimental results on oxidation state, morphology and functional behavior of nanostructures, and I will discuss open questions and future developments.

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SEMINAR on    Disorder and strong electron correlations

 

Friday, 4 March -  11:30 a.m.

 



Luigi Stasi Seminar Room,  Leonardo Building - first floor

 

 Andreas WEICHSELBAUM      ( Ludwig-Maximilians-Universität, München)

 

"Efficient simulation of quantum-many-body systems with tensor networks"

  

Abstract

 

In this talk I will give a brief review on the intrinsic link between the numerical renormalization group (NRG) and the density matrix renormalization group (DMRG) in terms of tensor networks.  With respect to the NRG then, complete yet fully tractable many-body basis sets allow for textbook evaluations of physical properties of quantum impurity models such as dynamic correlation functions or quantum quenches.  This, for example, also provides a direct link to optical absorption spectra, and provides a framework for a clean numerical treatment of Anderson orthogonality exponents in the thermodynamic limit.  More generally, challenges in numerical complexity will be addressed, highlighting a recent algorithmic advance in terms of the generic implementation of non-abelian symmetries within tensor networks.

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