Giant ground- and excited-state optical nonlinearity in one-dimensional cupratesHaranath Ghosh
Laser Physics Application section, Raja Ramanna Centre for Advanced Technology Indore 452013, India
received 26 April 2006; accepted in final form 9 June 2006
published online 30 June 2006
We present a mechanism of giant optical nonlinearity in one-dimensional Mott-Hubbard insulators and predict a few orders of magnitude higher excited-state optical non-linearity compared to that from the ground state. We show that not only the first excited one- and two-photon states are nearly degenerate but also higher-energy excited one- and two-photon states with very large dipole coupling between them are so. This is the cause for huge optical nonlinearity and higher excited-state optical nonlinearity. We also predict the presence of a higher-energy two-photon state through various optical properties to be experimentally verified. The gigantic excited-state optical nonlinearity predicted for Mott-Hubbard insulators, perhaps, may make these systems suitable for application in terahertz sources.
71.27.+a - Strongly correlated electron systems; heavy fermions.
78.20.Bh - Optical properties of bulk materials and thin films: Theory, models, and numerical simulation.
42.65.-k - Nonlinear optics.
© EDP Sciences 2006