Optimizing the efficiency of quantum emitters
ORAL · Invited
Abstract
Single-photon emitters are an essential component of quantum networks, and defects or impurities in semiconductors or insulators are a promising platform to realize such quantum emitters. Long-range networking using defect-based single-photon emitters has been demonstrated, mainly relying on the nitrogen-vacancy (NV) center in diamond. However, the optical interface of the NV center is far from ideal: less than 3% of the emitted photons are in the zero-phonon line (ZPL), i.e., useful for quantum information. This is a result of the interaction between the electronic states of the defect and the host lattice, referred to as electron–phonon coupling. Electron–phonon coupling also broadens the ZPL, leading to dephasing, which reduces indistinguishability.
We have developed a model, along with methodology based on first-principles calculations, that encapsulates the essential physics of coupling to phonons [1]. Electron-phonon coupling shapes the photoluminescence spectrum of a defect but also introduces nonradiative decay channels that play a crucial rule in limiting the efficiency, particularly at long wavelengths. These limitations impact single-photon emitters at telecom wavelengths, which are desirable because they would be compatible with low-loss optical fibers.
Our results suggest that reducing the phonon frequency is a fruitful avenue to enhance the efficiency. We also discuss various engineering approaches to mitigate the lower quantum efficiency. The issues will be illustrated with various examples of quantum emitters, particularly in cubic BN, a promising host material [2].
Work performed in collaboration with M. Turiansky, K. Parto, G. Moody, K. Czelej, M. R. Lambert, S. Mu.
[1] M. E. Turiansky, K. Parto, G. Moody, and C. G. Van de Walle, APL Photonics 9, 066117 (2024).
[2] M. E. Turiansky and C. G. Van de Walle, Phys. Rev. B 108, L041102 (2023).
We have developed a model, along with methodology based on first-principles calculations, that encapsulates the essential physics of coupling to phonons [1]. Electron-phonon coupling shapes the photoluminescence spectrum of a defect but also introduces nonradiative decay channels that play a crucial rule in limiting the efficiency, particularly at long wavelengths. These limitations impact single-photon emitters at telecom wavelengths, which are desirable because they would be compatible with low-loss optical fibers.
Our results suggest that reducing the phonon frequency is a fruitful avenue to enhance the efficiency. We also discuss various engineering approaches to mitigate the lower quantum efficiency. The issues will be illustrated with various examples of quantum emitters, particularly in cubic BN, a promising host material [2].
Work performed in collaboration with M. Turiansky, K. Parto, G. Moody, K. Czelej, M. R. Lambert, S. Mu.
[1] M. E. Turiansky, K. Parto, G. Moody, and C. G. Van de Walle, APL Photonics 9, 066117 (2024).
[2] M. E. Turiansky and C. G. Van de Walle, Phys. Rev. B 108, L041102 (2023).
–
Publication: [1] M. E. Turiansky, K. Parto, G. Moody, and C. G. Van de Walle, APL Photonics 9, 066117 (2024).<br><br>[2] M. E. Turiansky and C. G. Van de Walle, Phys. Rev. B 108, L041102 (2023).
Presenters
-
Chris G Van de Walle
University of California, Santa Barbara, Materials Department, University of California, Santa Barbara, CA 93106-5050, U.S.A.
Authors
-
Chris G Van de Walle
University of California, Santa Barbara, Materials Department, University of California, Santa Barbara, CA 93106-5050, U.S.A.