Deterministic photonic entanglement arising from non-Abelian quantum holonomy

Realizing deterministic, high-fidelity entangling interactions--of the kind that can be utilized for efficient quantum information processing--between photons remains an elusive goal. Here, we address this long-standing issue by devising a protocol for creating and manipulating highly-entangled superpositions of well-controlled states of light by using an on-chip photonic system that has recently been shown to implement three-dimensional, non-Abelian quantum holonomy. Our calculations indicate that a subset of such entangled superpositions are maximally-entangled, volume-law states, and that the underlying entanglement can be distilled and purified for applications in quantum science. Specifically, we envisage that this entangling mechanism could be utilized for realizing two-qubit, universal, entangling quantum gates with linear photonic elements alone. Furthermore, this method should also--at least, in principle--be generalizable to systems of neutral atoms.