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arXiv · 2510.23862

Giant Isotope Effect on the Excited-State Lifetime and Emission Efficiency of the Silicon T Centre

Moein Kazemi·Mehdi Keshavarz·Mark E. Turiansky·John L. Lyons·Nikolay V. Abrosimov·Stephanie Simmons·Daniel B. Higginbottom·Mike L. W. Thewalt
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Abstract

Efficient single-photon emitters are desirable for quantum technologies including quantum networks and photonic quantum computers. We investigate the T centre, a telecommunications-band emitter in silicon, and find a strong isotope dependence of its excited-state lifetime. In particular, the lifetime of the deuterium T centre is over five times longer than the common protium variant. Through explicit first-principles calculations, we demonstrate that this dramatic difference is due to a reduction in the carbon-hydrogen local vibrational mode energy, which suppresses non-radiative decay. Our results imply that the deuterium T centre approaches unit quantum efficiency, enabling more efficient single-photon sources, quantum memories, and entanglement generation.

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Moein Kazemi, Mehdi Keshavarz, Mark E. Turiansky, John L. Lyons, Nikolay V. Abrosimov, Stephanie Simmons, Daniel B. Higginbottom, Mike L. W. Thewalt. 2025-10-27. Giant Isotope Effect on the Excited-State Lifetime and Emission Efficiency of the Silicon T Centre. https://arxiv.org/abs/2510.23862

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