Giant conductance and phase time anomalous events of hole quantum transport

TL;DR

This paper theoretically investigates giant conductance and phase time anomalies for holes in quantum heterostructures, revealing new analytical relations and phenomena like early arrival times and filter effects in double barriers and superlattices.

Contribution

It introduces new analytical expressions for unitarity in hole transport and demonstrates giant conductance and phase time anomalies in heterostructures without valence-band mixing.

Findings

Giant conductance signatures found in hole transmission through heterostructures.

Early phase time arrival of holes within barriers, on the order of tenths of picoseconds.

Filter-like effects due to selective confinement of hole flavors.

Abstract

Events of giant conductance and anomalies of the phase transmission time for holes, are theoretically investigated within the multicomponent scattering approach. Based on this model, new analytical expressions for unitarity relations in the uncoupled hole transport are obtained and directly applied to study the behavior of the conductance and the phase transmission time in a double barrier resonant tunneling (DBRT) and a superlattice $GaAs$-cladding layer$/(AlAs/GaAs)^{n}/GaAs$-cladding layer. Clear-signature evidences of giant conductance phenomena for hole transmission without valence-band mixing through a DBRT and a superlattice were found. The giant conductance effect losses robustness by manipulating the number of superlattice layers and by including the valence-band particles coupling as well. Phase time through the heterostructure exhibits extremal dependencies in the gaps and in the barriers, as those reported before for electrons. We have detected an earlier arrival phase time for the propagation of both flavors of holes within the barrier, in the order of few tenths of picoseconds. An appealing filter-like effect is presented, whenever a selective confinement strength arises independently for both flavors of holes in the uncoupled regime. Our results also prescribe noticeable evidences for both uncoupled and coupled hole fluxes, similar to those foretold by Hartman, upon transmission of electrons through opaque barriers.