Next weeks' seminars

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

JOINT ICTP/SISSA STATISTICAL PHYSICS SEMINAR



Tuesday, 11 May   -   11:30 hrs.



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



Rosario FAZIO     (Scuola Normale Superiore, Pisa)



"Critical exponents of many-body quantum systems by means of the   
Multiscale Entanglement Renormalization Ansatz"



Abstract



The selection of suitable tailored variational wavefunctions is a  
fundamental problem in the study of quantum many-body systems.   
Variational approaches based on tensor networks are a novel powerful  
numerical tool believed to be the key ingredient to simulate  
efficiently quantum-many body systems. Among the proposed tensor  
networks, a very promising one is the so-called Multiscale  
Entanglement Renormalization Ansatz (MERA).  I will discuss how to  
extract the critical exponents from the MERA ansatz and apply the  
method to a number of one-dimensional spin models.

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  JOINT ICTP/SISSA CONDENSED MATTER SEMINAR



Wednesday, 12 May -     4:00 p.m.



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





Thomas BLIGAARD    (Technical University of Denmark, Lyngby)



"Towards computational design of heterogeneous catalysts"



Abstract



Scaling relations are presented which have the capability to estimate  
adsorbate-surface bond energies for hydrogen-containing molecules on  
transition metal surfaces with reasonable accuracy. The relations  
provide a method for estimating hydrogenation reaction energies,  
leading to new possibilities in using electronic structure simulations  
in the search for new catalysts.  Using the selective hydrogenation of  
acetylene to ethylene as an example, it is shown how the adsorption  
energy of one single species can be used as a descriptor for the  
catalytic activity and selectivity.  A number of alloys are  
investigated and new catalysts are singled out and experimentally  
tested, leading to the suggestion of new potential catalysts not  
containing precious metals.  That scaling relations hold for  
adsorption energies of molecules larger than one carbon atom, suggests  
they can provide a method for treating the surface chemistry of more  
complex hydrocarbons.  It is finally shown that the scaling model  
surprisingly can be generalized to the surfaces of more complex  
materials such as oxides and nitrides.