Hy-Q Colloquium by Mark Spencer Rudner, Condensed Matter Physics, NBI – University of Copenhagen

Hy-Q Colloquium by Mark Spencer Rudner, Condensed Matter Physics, NBI

Chiral plasmons without magnetic field


Abstract:
Chirality, or "handedness," is an important property that shows up in a variety of settings from biology, to chemistry, and physics. In physics, the appearance of chirality (implying a difference between right and left) can be a sign of intriguing new fundamental physics, and may also form the basis for interesting new device functionality.  In this talk I will describe how the novel characteristics of quantum materials with non-vanishing Bloch-band Berry curvature may give rise to a novel type of chiral plasmonic modes that propagate along sample boundaries. These "chiral Berry plasmons" (CBPs) arise naturally in materials with broken time-reversal symmetry, such as magnetically-doped topological insulators, and may also be induced dynamically in non-magnetic materials with broken inversion symmetry via optical pumping of valley polarization.  In addition to being of fundamental interest, CBPs may provide means for on-chip, magnetic field free, and on-demand non-reciprocal signal propagation.