"Shell structure and signature of high-temperature pairing in size selected metal nano clusters"

Speaker: 
Vitaly Kresin
Institution: 
Univ. of Southern Cal. (USC)
Date: 
Wednesday, June 3, 2015
Time: 
4:00 pm
Location: 
NS2 1201
 

 
 
ABSTRACT:  
 
Nanoclusters are agglomerates of a countable number of atoms or molecules, from a few to thousands.  They form a bridge between individual molecules, and quantum dots and bulk materials.  By studying the properties of size-resolved clusters their evolution can be traced electron-by-electron and atom-by-atom.   Delocalized electrons in metal nanoclusters organize into a “superatom” shell structure which governs the particles’ stabilities, shapes, and other properties.  These highly degenerate shell levels represent sharp peaks in the electronic density of states and give rise to the possibility of exceptionally strong superconducting pairing in specific individual nanoclusters.  This has been confirmed in our recent spectroscopic study of size-resolved free aluminum clusters which revealed a transition at approximately 100 K, exceeding the critical temperature of the bulk metal by two orders of magnitude.  The experimental observation of pairing in nanocluster particles introduces an entirely new class of high-temperature superconductors and highlights their potential as building blocks for materials and tunneling networks.
 
 

 
Host: 
Ilya Krivorotov