Giant Stark effect in coupled quantum wells: Analytical model

Abstract

Coupled quantum wells have been proposed as candidates for highly polarizable structures due to their neardegenerate and dipole-coupled electronic states. Hence, many interesting applications in linear and nonlinear optics can be envisioned. We analyze this proposal considering a simple structure with a delta-function barrier separating the wells. While very substantial Stark shifts are certainly predicted for this geometry, perturbative estimates based on polarizabilities (and hyperpolarizabilities) fail beyond a critical field strength that depends inversely on the barrier. Hence, a giant Stark effect due to near-degenerate states is invariably limited by a small critical field. Our analytical (hyper) polarizability expressions are applied to find quantitative Stark shifts for GaAs quantum wells and transition-metal dichalcogenide bilayers. The predicted Stark shifts and critical fields agree with the field dependence observed in a range of available experiments.

An analytical model for electron tunneling in triangular quantum wells

“…Airy function method is also explored previously by Ahn and Chuang [9] for Stark resonance in quantum wells, however, the resonance width and location is calculated numerically. Giant Stark effect has been studied for triangular quantum wells with the aid of Airy function solutions by Pedersen [20]. Excitonic states in AlGaAs and InGaAs coupled quantum wells have been analyzed in [21] where the complex energy exciton eigenstates and wavefunctions have been calculated numerically.…”

Anisotropic exciton Stark shift in hemispherical quantum dots

“…[17][18][19][20][21][22] In the past decades, the QCSE in semiconductor nanostructures has become increasingly popular due to the potential applications in both fundamental physics and device applications. [23][24][25][26][27][28][29][30][31][32][33] There are two types of QCSEs. The first type offers tailorable optical response that can be used in devices like high-speed optical modulators.…”