High-field wave packets in semiconductor quantum wells: A real-space finite-difference time-domain formalism

Abstract

An untraditional space-time method for describing the dynamics of high-field electron-hole wave packets in semiconductor quantum wells is presented. A finite-difference time-domain technique is found to be computationally efficient and can incorporate Coulomb, static, terahertz, and magnetic fields to all orders, and thus can be applied to study many areas of high-field semiconductor physics. Several electro-optical and electromagneto-optical excitation schemes are studied, some well known and some new, and predicted observables are shown to be in qualitative agreement with experiment, where known.

An analytical investigation of excitonic absorption in terahertz-driven quantum wells

“…Later, the excitonic e ect due to Coulomb interaction between electrons and holes is also included in the consideration. [6][7][8][9][10][11][12][13] Excitonic absorption in a variety of semiconductor nanostructures under strong THz eld in di erent structures and con gurations are also investigated, such as quantum wells with 14 and without a magnetic eld in the presence, 15 asymmetric coupled double quantum wells, 16 quantum wires, 17 quantum rings, 18 and quantum dot superlattices. 19 These studies show that when a near-infrared (NIR) eld and a THz eld are incident to semiconductor nanostructures, and if the NIR eld is resonant with an excitonic transition and the terahertz electric eld resonantly couples to intersubband transitions or two excitonic transitions, THz optical sidebands on the NIR carrier beam are generated.…”

Autler-Townes splitting and quantum confined Stark effect of sideband peak in asymmetric double quantum wells

“…In general, the theoretical works on the optical absorption dynamic behavior in semiconductor nanostructure have been implemented based on various formulations, such as Green's function techniques, 9,23,24 the density matrix approach, 18,20 the semiconductor Bloch equation, 3,4,15,16 the inhomogenous Schrodinger equation, 25 and the master equation approach. 26 Though the optical absorption properties of the semiconductor QW system have been studied many times, the dependence of the total carrier density on time is generally neglected by the quasi-equilibrium approximation.…”