next Tues. seminar

[Condensed_Matter_Group]

JOINT ICTP/SISSA STATISTICAL PHYSICS SEMINAR



Tuesday, 13 December  -   11:00 hrs.




SISSA, Santorio Building, Room 128 (1st Floor)





R.M. KONIK  ( Brookhaven National Laboratories )




"Exciton hierarchies in carbon nanotubes"



Abstract


I present evidence that the strong electron-electron interactions in  
gapped carbon nanotubes lead to finite hierarchies of excitons within   a
given nanotube subband. I study these hierarchies by employing a   field
theoretic reduction of the gapped carbon nanotube permitting  
electron-electron interactions to be treated exactly. I analyze this  
reduction by employing a Wilsonian-like numerical renormalization   group.
I am so able to determine the gap ratios of the one-photon   excitons as a
function of the effective strength of interactions. I   also determine
within the same subband the gaps of the two-photon   excitons, the single
particle gaps, as well as a subset of the dark   excitons. The strong
electron-electron interactions in addition lead   to strongly renormalized
dispersion relations where the consequences   of spin-charge separation
can be readily observed.