Low Temperature Spectroscopy of hBN Quantum Emitters

Mouli Hazra
Technical University of Munich – Munich, Germany
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Hexagonal boron nitride (hBN) is known to host a diverse range of high-quality single-photon emitters (SPEs), establishing its potential as a promising material for quantum technology applications. For these emitters to be used in practice, their spatial localisation and emission wavelengths must be precisely controlled. In this work, we used electron beam irradiation to hit hBN flakes and studied the creation of SPEs close to the irradiated areas. We then investigated the photophysical characteristics of these emitters at low temperatures. Additionally, we looked into how their emission characteristics were affected by the excitation wavelength. By systematically varying the excitation wavelength, we successfully distinguished the zero-phonon line associated with the hBN emitters from the Raman signal, as well as identify the phonon modes. Furthermore, we conducted a detailed analysis of the temperature-dependent behaviour of their emission, where we found a reduction of the Debye-Waller factor with increasing temperature. This work represents an advancement toward the yellow quantum emitter defect fabricated by electron beam irradiation.

References
[1] Kumar, Anand, et al. “Localized creation of yellow single photon emitting carbon complexes in hexagonal boron nitride.” APL Materials 11.7 (2023).
[2] Kumar, Anand, et al. “Polarization dynamics of solid-state quantum emitters.” ACS nano 18.7 (2024): 5270-5281.

Email: mouli.hazra@tum.de