Nonequilibrium Band Mapping of Unoccupied Bulk States below the Vacuum Level by Two-Photon Photoemission
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 {h_bar}{omega}, are in excellent agreement with tight-binding band-structure calculations. The variation of the final-state energy with {h_bar}{omega} has a measured slope of -1.64 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 {h_bar}k{perpendicular} in 2PPE.
- Research Organization:
- BROOKHAVEN NATIONAL LABORATORY (BNL)
- Sponsoring Organization:
- Doe - Office Of Science
- DOE Contract Number:
- AC02-98CH10886
- OSTI ID:
- 988772
- Report Number(s):
- BNL--93823-2010-JA; KC0202020
- Journal Information:
- Physical Review Letters, Journal Name: Physical Review Letters Journal Issue: 1 Vol. 105; ISSN 0031-9007; ISSN PRLTAO
- Country of Publication:
- United States
- Language:
- English
Similar Records
Intensity oscillations in the inverse photoemission cross section of an unoccupied surface state on Cu(001)
Photoemission spectra and band structures of d-band metals. XI. Inverse photoemission from Pd(111)