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Sonny
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Chromium Impurity Characterization in beta-Ga2O3 as a Quantum Defect
Combined first-principles and experimental characterization of chromium in monoclinic beta-Ga2O3, a wide-bandgap semiconductor. Cr incorporates preferentially as a neutral impurity on the octahedral site with a quartet ground-state spin and an internal zero-phonon-line transition near 1.8 eV (reminiscent of ruby). Matching the calculated and measured photoluminescence lineshape reveals coupling to phonons beyond the Franck-Condon approximation; the strong emission combined with a small Huang-Rhys factor (0.05) makes Cr in Ga2O3 attractive as a quantum defect for spin-photon qubits.