Nanophotonic Quantum Skyrmions Empowered by Semiconductor Cavity Quantum Electrodynamics

Skyrmions are topologically stable quasiparticles that have been investigated in a variety of branches in modern physics including particle physics, quantum field theory, solid-state physics, acoustics and condensed-matter physics. The recent exploration of skyrmions in classical optics exhibits the transformative potential of photonic information technology. The quantum optical skyrmion with local topological textures is expected to profoundly reshape the landscape of quantum photonic technology yet its experimental realization remains elusive. Here, we present realizations of nanophotonic quantum skyrmions created by a semiconductor cavity quantum electrodynamics system. By carefully engineering the photonic spin-orbit coupling in a Gaussian microcavity, we construct a confined optical mode whose polarizations feature skyrmionic topologies. With pronounced cavity quantum electrodynamics effects, single-photon skyrmions are generated from a solid-state quantum emitter deterministically coupled to the Gaussian microcavity. The polarity associated with single-photon skyrmions can be swapped by flipping the polarization of the quantum emitter via the Zeeman effect. We further investigate the topological protection of quantum optical skyrmions under different perturbations. Our work opens an unexplored paradigm of quantum light-matter interactions in the nanoscale and may advance resilient photonic quantum technology with high-dimensional qubits and high-capacity quantum memories.