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Register a new userQuantum optics with single spins
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Authors
Lee C. Bassett
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Defects in solids are in many ways analogous to trapped atoms or molecules. They can serve as long-lived quantum memories and efficient light-matter interfaces. As such, they are leading building blocks for long-distance quantum networks and distributed quantum computers. This chapter describes the quantum-mechanical coupling between atom-like spin states and light, using the diamond nitrogen-vacancy (NV) center as a paradigm. We present an overview of the NV centers electronic structure, derive a general picture of coherent light-matter interactions, and describe several methods that can be used to achieve all-optical initialization, quantum-coherent control, and readout of solid-state spins. These techniques can be readily generalized to other defect systems, and they serve as the basis for advanced protocols at the heart of many emerging quantum technologies.
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Under ambient conditions, spin impurities in solid-state systems are found in thermally-mixed states and are optically dark, i.e., the spin states cannot be optically controlled. Nitrogen-vacancy (NV) centers in diamond are an exception in that the electronic spin states are bright, i.e., they can be polarized by optical pumping, coherently manipulated with spin-resonance techniques, and read out optically, all at room temperature. Here we demonstrate a dressed-state, double-resonance scheme to transfer polarization from bright NV electronic spins to dark substitutional-Nitrogen (P1) electronic spins in diamond. This polarization-transfer mechanism could be used to cool a mesoscopic bath of dark spins to near-zero temperature, thus providing a resource for quantum information and sensing, and aiding studies of quantum effects in many-body spin systems.
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