Observation of a chiral state in a microwave cavity

Phys Rev Lett. 2003 Jan 24;90(3):034101. doi: 10.1103/PhysRevLett.90.034101. Epub 2003 Jan 23.

Abstract

A microwave experiment has been realized to measure the phase difference of the oscillating electric field at two points inside the cavity. The technique has been applied to a dissipative resonator which exhibits a singularity-called exceptional point-in its eigenvalue and eigenvector spectrum. At the singularity, two modes coalesce with a phase difference of pi/2. We conclude that the state excited at the singularity has a definitive chirality.