In the 1980s, theoretical estimates showed that on macroscopic scales I decoherence occurs extremely rapidly, thus effectively precluding the observation of nonclassical I superposition states [21–23]. This immediately led to the question of how we may experimentally observe the continuous action of decoherence and thus the smooth transition from quantum to classical. Several challenges have to...

Interorbital coupling refers to the possibility of exciting orbital states by otherwise orthogonal noninteracting modes, a forbidden process in photonic lattices due intrinsic propagation constant detuning. In this Letter, using femtosecond (fs) laser writing technique, we experimentally demonstrate that fundamental and excited can couple each other when located at different spatial positions. ...

In 1929, Hermann Weyl derived [1] the massless solutions from the Dirac equation – the relativistic wave equation for electrons. Neutrinos were thought, for decades, to be Weyl fermions until the discovery of the neutrino mass. Moreover, it has been suggested that low energy excitations in condensed matter[2–8] can be the solutions to the Weyl Hamiltonian. Recently, photons have also been propo...