Compressive and tensile strain effects on hole tunneling in an InGaAs/AlInAs asymmetrical coupled quantum well

Hole tunneling dynamics are investigated in a strained asymmetrical coupled quantum well (ACQW). The tunneling probabilities between heavy-hole states are calculated at different internal strains on the basis of the time-dependent Schrödinger equation analysis with the Luttinger-Kohn and an additional strain Hamiltonians. In a certain range of strain, a higher oscillation frequency (but a smaller oscillation amplitude) of hole tunneling at resonance is obtained in a biaxial tensile strain ACQW at in-plane wave vector k =0. The biaxial compressive strain is observed to lower the oscillation frequency. With a nonzero wave vector (k≠0), the oscillation frequency is found to be dominated by mixing effects and less dependent on the internal strain. The oscillation frequency remains roughly constant; however, the biaxial compressive strain ACQWs would still have a larger oscillation amplitude than biaxial tensile strain ACQWs.