Valley splitting in V-shaped quantum wells

The valley splitting senergy difference between the states of the lowest doubletd in strained silicon quantum wells with a V-shaped potential is calculated variationally using a two-band tight-binding model. The approximation is valid for a moderately long sapproximately 5.5–13.5 nmd quantum well with a V-shaped potential which can be produced by a realistic delta-doping on the order of nd<10 cm−2. The splitting versus applied field ssteepness of the V-shaped potentiald curves show interesting behavior: a single minimum and for some doublets, a parity reversal as the field is increased. These characteristics are explained through an analysis of the variational wave function and energy functional. © 2005 American Institute of Physics. fDOI: 10.1063/1.1913798g