Nonequilibrium band mapping of unoccupied bulk states below the vacuum level by two-photon photoemission.
Phys Rev Lett
; 105(1): 017602, 2010 Jul 02.
Article
in En
| MEDLINE
| ID: mdl-20867478
ABSTRACT
We demonstrate angle-resolved, tunable, two-photon photoemission (2PPE) to map a bulk unoccupied band, viz. the Cu sp band 0 to 1 eV below the vacuum level, in the vicinity of the L point. This short-lived bulk band is seen due to the strong optical pump rate, and the observed transition energies and their dispersion with photon energy âω, are in excellent agreement with tight-binding band-structure calculations. The variation of the final-state energy with âω has a measured slope of â¼1.64 in contrast to values of 1 or 2 observed for 2PPE from two-dimensional states. This unique variation illustrates the significant role of the perpendicular momentum âk_{â¥} in 2PPE.
Search on Google
Collection:
01-internacional
Database:
MEDLINE
Language:
En
Journal:
Phys Rev Lett
Year:
2010
Document type:
Article
Affiliation country:
United States