Researchers demonstrate Rashba-like spin splitting in a perfectly symmetric plasmonic crystal, challenging conventional assumptions about the role of structural asymmetry

Spinning light interaction abstract (Courtesy: iStock/Sakkmesterke)

When a material does not have inversion symmetry, particles within it will move in different directions when they have different spin states. This is because the asymmetry of the material creates an effective electric field that couples the particles’ spin and momentum. The behaviour is called the Rashba effect, and it allows researchers to manipulate electron spins without requiring a magnetic field.

Surface plasmons are waves of oscillating electrons that travel along a metal surface when it interacts with light. In this work, the researchers investigated surface plasmons to see if they could create something like the Rashba effect but in a completely symmetrical material.…