Spectral maximum in the terahertz photoconductance of a quantum point contact

TL;DR

This paper explains the disappearance of giant terahertz photoconductance in quantum point contacts at higher photon energies, attributing it to momentum conservation and perturbation theory calculations.

Contribution

It provides a theoretical explanation for experimental observations of photoconductance behavior in quantum point contacts at terahertz frequencies.

Findings

Photoconductance diminishes with increasing photon energy.

Momentum conservation limits photon absorption effects.

Perturbation theory accurately models the observed phenomena.

Abstract

The disappearance of the giant terahertz photoconductance of a quantum point contact under the increase in the photon energy, which was discovered experimentally (Otteneder et al., Phys. Rev. Applied 10 (2018) 014015) and studied by the numerical calculations of the photon-stimulated transport (O.A. Tkachenko et al., JETP Lett. 108 (2018) 396), is explained by the momentum conservation upon absorption of photons by tunneling electrons and on the base of perturbation theory calculations.