Supercollimation of pseudospin-1 electromagnetic wave packets in a disordered layered photonic structure

We investigate the propagation of pseudospin-1 electromagnetic (EM) wave packets through one-dimensional (1D) disordered layered structures. For sufficiently strong disorder, the wave packet propagates virtually undistorted along the potential fluctuation direction, independent of its incident angle. Moreover, stronger disorder yields better supercollimation. This phenomenon persists in every single disorder realization, in contrast to graphene, where it requires ensemble averaging. It originates from the conical dispersion, leading to anomalous Anderson localization, transverse displacement cancellation, and longitudinal phase compensation. Our findings reveal the significant role of pseudospin in quasiparticle transport and open new avenues for designing disorder-resilient devices based on pseudospin-1 photonic crystals (PCs).