Floquet scattering of quadratic band-touching semimetals through a time-periodic potential well

TL;DR

This paper investigates how quasiparticles in quadratic band-touching semimetals tunnel through a time-periodic potential well, revealing Fano resonances in transmission and shot noise spectra using Floquet theory.

Contribution

It introduces a Floquet scattering matrix approach to analyze quasiparticle tunneling in QBT semimetals under periodic driving, highlighting resonance phenomena.

Findings

Identification of Fano resonances in spectra

Derivation of Floquet scattering matrices

Analysis of bound states in QBT semimetals

Abstract

We consider tunneling of quasiparticles through a rectangular quantum well, subject to periodic driving. The quasiparticles are the itinerant charges in two-dimensional and three-dimensional semimetals having a quadratic band-touching (QBT) point in the Brillouin zone. In order to analyze the time-periodic Hamiltonian, we assume a non-adiabatic limit, where the Floquet theorem is applicable. By deriving the Floquet scattering matrices, we chalk out the transmission and shot noise spectra of the QBT semimetals. The spectra show Fano resonances, which we identify with the (quasi)bound states of the systems.