Barrier tunneling of the Loop-Nodal Semimetal in the Hyperhoneycomb lattice

TL;DR

This paper explores how electrons tunnel through barriers in a three-dimensional hyperhoneycomb lattice, revealing conditions for high transmission and resonant oscillations in a nodal-line semimetal with a Dirac loop.

Contribution

It provides the first analytical and numerical analysis of barrier tunneling in hyperhoneycomb lattice semimetals, highlighting conditions for perfect transmission and resonant behavior.

Findings

High transmission occurs near the nodal loop plane.

Resonant oscillations in transmission depend on potential energy.

Perfect transmission peaks are robust against potential width.

Abstract

We theoretically investigate the barrier tunneling in the three-dimensional model of the hyperhoneycomb lattice, which is a nodal-line semimetal with a Dirac loop at zero energy. In the presence of a rectangular potential, the scattering amplitudes for different injecting states around the nodal loop are calculated, by using analytical treatments of the effective model, as well as numerical simulations of the tight binding model. In the low energy regime, states with remarkable transmissions are only concentrated in a small range around the loop plane. When the momentum of the injecting electron is coplanar with the nodal loop, nearly perfect transmissions can occur for a large range of injecting azimuthal angles if the potential is not high. For higher potential energies, the transmission shows a resonant oscillation with the potential, but still with peaks being perfect transmissions that do not decay with the potential width. These robust transports of the loop-nodal semimetal can be approximately explained by a momentum dependent Dirac Hamiltonian.