We present a complete and consistent quantum theory of generalised X waves
with orbital angular momentum (OAM) in dispersive media. We show that the
resulting quantised light pulses are affected by neither dispersion nor
diffraction and are therefore resilient against external perturbations. The
nonlinear interaction of quantised X waves in quadratic and Kerr nonlinear
media is also presented and studied in detail.
[1704.07258] Quantum X Waves with Orbital Angular Momentum in Nonlinear Dispersive Media