The switching ability of a three-level tight-binding system: the isolated and embedded case

Abstract

The control of the dynamics of a tight-binding isolated three-level system prepared in a non-stationary initial state is studied as a function of its two control parameters: alpha a^-1, the ratio of the coupling to the energy difference between the initial, the target and the intermediate state, and beta alpha ^-1, the asymmetry parameter of the coupling between these states. When the system is embedded in a periodic chain, alpha a^-1 and beta alpha ^-1 control the low-voltage conductance G of the whole system. The control law of the average transmission coefficient T_eff (with G=T_eff(1-T_eff)^-1) is found to be the same as the control law of the minimum distance between the initial and the target state in the isolated case. The control abilities of alpha a^-1 and beta alpha ^-1 are analytically studied and optimised in the isolated and embedded case.