Antiresonance induced by symmetry-broken contacts in quasi-one-dimensional lattices

TL;DR

This paper investigates how symmetry-breaking contacts affect quantum transport in quasi-one-dimensional lattices, revealing antiresonance phenomena and providing a method to detect flat band energies.

Contribution

It demonstrates the impact of contact symmetry on transport properties and introduces a way to identify flat band energies through antiresonance effects.

Findings

Asymmetric contacts induce antiresonance and suppress transmission at specific energies.

Symmetry-breaking contacts can reveal flat band energies in quasi-one-dimensional lattices.

Transport behavior is significantly altered by contact symmetry and on-site potential imbalance.

Abstract

We report the effect of symmetry-broken contacts on quantum transport in quasi-one-dimensional lattices. In contrast to 1D chains, transport in quasi-one-dimensional lattices, which are made up of a finite number of 1D chain layers, is strongly influenced by contacts. Contact symmetry depends on whether the contacts maintain or break the parity symmetry between the layers. With balanced on-site potential, a flat band can be detected by asymmetric contacts, but not by symmetric contacts. In the case of asymmetric contacts with imbalanced on-site potential, transmission is suppressed at certain energies. We elucidate these energies of transmission suppression related to antiresonance using reduced lattice models and Feynman paths. These results provide a nondestructive measurement of flat band energy which it is difficult to detect.