Ultrafast optical nonlinearity in the quasi-one-dimensional mott insulator Sr2CuO3

T Ogasawara; M Ashida; N Motoyama; H Eisaki; S Uchida; Y Tokura; H Ghosh; A Shukla; S Mazumdar; M Kuwata-Gonokami

doi:10.1103/PhysRevLett.85.2204

Ultrafast optical nonlinearity in the quasi-one-dimensional mott insulator Sr2CuO3

Phys Rev Lett. 2000 Sep 4;85(10):2204-7. doi: 10.1103/PhysRevLett.85.2204.

Authors

T Ogasawara¹, M Ashida, N Motoyama, H Eisaki, S Uchida, Y Tokura, H Ghosh, A Shukla, S Mazumdar, M Kuwata-Gonokami

Affiliation

¹ Department of Applied Physics, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo, 113-8656, Japan.

PMID: 10970498
DOI: 10.1103/PhysRevLett.85.2204

Abstract

We report strong instantaneous photoinduced absorption in the quasi-one-dimensional Mott insulator Sr2CuO3 in the IR spectral region. The observed photoinduced absorption is to an even-parity two-photon state that occurs immediately above the absorption edge. Theoretical calculation based on a two-band extended Hubbard model explains the experimental features and indicates that the strong two-photon absorption is due to a very large dipole coupling between nearly degenerate one- and two-photon states. Room temperature picosecond recovery of the optical transparency suggests the strong potential of Sr2CuO3 for all-optical switching.