Tunable terahertz plasmons in graphite thin films

TL;DR

This paper demonstrates strong, tunable terahertz plasmons in graphite thin films, showing significant modulation via temperature and bias, and reveals the roles of electrons and Dirac holes in the plasmon response.

Contribution

It introduces a new platform for tunable terahertz plasmons in graphite, highlighting their strong response and the interplay of different charge carriers.

Findings

Strong terahertz plasmons observed in graphite thin films.

Tunable response achieved through temperature and bias voltage.

Electrons and Dirac holes both contribute to plasmon behavior.

Abstract

Tunable terahertz plasmons are essential for reconfigurable photonics, which have been demonstrated in graphene through gating, though with relatively weak responses. Here, we demonstrate strong terahertz plasmons in graphite thin films via infrared spectroscopy, with dramatic tunability by even a moderate temperature change or an in-situ bias voltage. Meanwhile, through magneto-plasmon studies, we reveal that massive electrons and massless Dirac holes make comparable contributions to the plasmon response. Our study not only sets up a platform for further exploration of two-component plasmas, but also opens an avenue for terahertz modulation through electrical bias or all-optical means.