  We present a numerical framework of the new Langevin noise (LN) formalism
[1,2] leveraging computational electromagnetics numerical methods to analyze
quantum electromagnetic systems involving both medium and radiation losses. We
then perform fully quantum-theoretic numerical simulations to retrieve quantum
plasmonic Hong-Ou-Mandel (HOM) effects, demonstrated in recent experimental
works [3-5], due to plasmonic interferences of two indistinguishable bosonic
particles occupied in surface plasmon polariton (SPP) fields. The developed
numerical framework would pave the path towards quantitative evaluations of
open and dissipative quantum optics problems with the medium inhomogeneity and
geometric complexity, e.g., quantum plasmonic phenomena and metasurface-based
devices, useful for advancing the current quantum optics technology.
