Single-Shot Readout of a Solid-State Spin in a Decoherence-Free Subspace

This is the authors' abstract. We don't add key points for this paper.

``Molecules'' of coupled quantum dots offer efficient single-photon emission and spin qubits with long coherence times, positioning them as promising platforms for quantum information processing. The authors propose a protocol for reading out a quantum dot molecule's spin state, by means of of a microwave {π}-pulse and cycling of isolated optical transitions. Simulations show that the protocol can provide single-shot readout, given a realistic photon collection efficiency of 0.12%. Realizing such efficient spin readout could boost the potential of quantum dots for generating photon entanglement, storing quantum information, and serving as building blocks of quantum networks.