Rest Frame Interference in Rotating Structures and Metamaterials.

Using the formulation of electrodynamics in rotating media, we put into explicit quantitative form the effect of rotation on interference and diffraction patterns as observed in the rotating medium's rest frame. As a paradigm experiment we focus the interference generated by a linear array of sources in a homogeneous medium. The interference is distorted due to rotation; the maxima now follow curved trajectories. Unlike the classical Sagnac effect in which the rotation induced phase is independent of the refraction index n, here the maxima bending increases when n decreases, suggesting that ε-near-zero metamaterials can enhance optical gyroscopes and rotation-induced nonreciprocal devices. This result is counterintuitive as one may expect that a wave that travels faster would bend less. The apparent contradiction is clarified via the Minkowski momentum picture for a quasiparticle model of the interference that introduces the action of a Coriolis force, and by the Abraham picture of the wave-only momentum. Our results may also shed light on the Abraham-Minkowski controversy as examined in noninertial electrodynamics.