I will discuss our recent proposal on deterministic generation of photonic repeater graph states using only a single quantum emitter, our plans for its experimental implementation, and its applications in quantum repeaters and networks.
Photons are excellent carriers of quantum information; their polarization remains coherent for long times and it is easy to measure and precisely rotate. The fundamental hurdle with photon-based quantum information processing is the lack of direct photon-photon interactions to provide entanglement between pairs of photons. Recent proposals show the ability to build large cluster states from small entangled states using non-deterministic operations, but the generation of deterministic high-fidelity small entangled states remains a challenge. In this talk, we will show how the necessary cluster-state building blocks for large-scale quantum computation can be created from coupled solid-state quantum emitters without the need for any two-qubit gates and regardless of whether the emitters are identical. We provide a recipe for the generation of two-dimensional, ‘cluster-state’ entangled photons that can be carried out with existing experimental capabilities.
We propose and analyze deterministic protocols to generate qudit photonic graph states from quantum emitters. We show that our approach can be applied to generate any qudit graph state and we exemplify it by constructing protocols to generate one- and two-dimensional qudit cluster states, absolutely maximally entangled states, and logical states of quantum error-correcting codes. Some of these protocols make use of time-delayed feedback, while others do not. The only additional resource requirement compared to the qubit case is the ability to control multilevel emitters. These results significantly broaden the range of multiphoton entangled states that can be produced deterministically from quantum emitters. Published by the American Physical Society 2024