Why hyperpolarizabilities fall short of the fundamental quantum limits.
Quantum sum rules impose limits on the hyperpolarizability, beta. A survey of the largest second-order molecular susceptibilities finds what appears to be a universal gap between the experimental results and the fundamental limits. In this work, we use theory, linear spectroscopy, Raman spectroscopy, and measured values of beta (using hyper-Rayleigh scattering and Stark Spectroscopy) to show that this gap is due to an unfavorable arrangement of excited state energies. The question of whether this result is a universal property of a quantum system or a matter of present paradigms for making molecules is discussed.
Department of Physics, Washington State University, Pullman, WA 99164-2814, USA.
Kakoli
K
Tripathy
Javier Pérez
JP
Moreno
Mark G
MG
Kuzyk
Benjamin J
BJ
Coe
Koen
K
Clays
Anne Myers
AM
Kelley