2 Special Seminars coming up

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

CONDENSED MATTER AND  STATISTICAL PHYSICS SECTION
 
 
SPECIAL SEMINAR
 

 

Friday, 10 February -    11:30 a.m.




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

 


Peter KIRTON      (University of Nottingham)

 

"Quantum current noise in a superconducting single electron transistor"


Abstract

 

We present a method for calculating the asymmetric quantum current noise in systems described by a Born-Markov master equation.  The technique is particularly suited to describing mesoscopic devices containing Josephson junctions.   As an example we calculate the full frequency dependent current noise in a superconducting single electron transistor tuned to the double Josephson quasiparticle resonance.  Our results are consistent with those obtained in a recent experiment which was able to probe the asymmetric noise.

=============



SPECIAL SEMINAR
 

 
Monday, 13 February -    10:30 a.m.

 
 

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

 

Sandip DE     (University of Basel)


 

"Energy landscape of fullerene materials:   A comparison of boron to boron nitride and carbon"



Abstract

 
After the discovery of the C60 fullerene some 25 years ago, many more hollow and endohedrally doped structures made out of various elementshave been proposed theoretically. However, since no other fullerenes have been synthesized up to date , the question arises whether experimentalists have just not yet found a way to synthesize these theoretically predicted fullerenes, or whether they do not exist at all in nature.

Following the theoretical discovery of the B_80 fullerene by Szwacki  et al, various other fullerene and stuffed fullerene structures were proposed but none of them could be synthesized in the  laboratory yet.  Using the minima hopping global geometry optimization  method on the density functional potential energy surface we show that the  energy landscape of boron clusters is glass like.

Medium size boron clusters exhibit many structures which are lower in  energy than the cages. This is in contrast to carbon and boron nitride systems which can be  clearly identified as structure seekers. The differences in the potential energy landscape explain why carbon and  boron nitride systems are found in nature whereas pure boron fullerenes have not been found. We thus present a methodology which can make predictions on the feasibility of the synthesis of new nano structures.