Justin Song (A*STAR & NTU, Singapore)
Wed, 06/04/2016 – 11:00am to 12:00pm
Physics Conference Room (S11-02-07)
Plasmons, the collective oscillations of interacting electrons, possess emergent properties that dramatically alter the optical response properties of metals. We predict the existence of a new class of plasmons – chiral Berry plasmons (CBPs) – for a wide range of metallic systems including anomalous Hall metals and gapped Dirac materials. As we show, in these materials the interplay between Berry curvature and electron-electron interactions yields chiral plasmonic modes at zero magnetic field. The CBP modes are confined to system boundaries, even in the absence of topological edge states, with chirality manifested in split energy dispersions for oppositely directed plasmon waves.
We unveil a rich CBP phenomenology and propose setups for realizing them, including in anomalous Hall metals and optically-pumped 2D Dirac materials. Realization of CBPs will offer a new paradigm for magnetic field-free, sub-wavelength optical non-reciprocity, in the mid IR-THz range, with tunable splittings as large as tens of THz, as well as sensitive all-optical diagnostics of topological bands.