Owing to their ability to generate non-classical light states, quantum dots (QDs) are very promising candidates for the large-scale implementation of quantum information technologies. However, the high photon collection efficiency demanded by these technologies may be impossible to reach for “standalone” semiconductor QDs, embedded in a high-refractive index medium. In this work a novel laser writing technique is presented, enabling the direct fabrication of a QD self-aligned—with a precision of ±30 nm—to a dielectric microsphere. The presence of the microsphere leads to an enhancement of the QD luminescence collection by a factor 7.3 ± 0.7 when an objective with 0.7 numerical aperture is employed. This technique exploits the possibility of breaking the N−H bonds in GaAs (Formula presented.) Nx:H by a laser light, obtaining a lower-bandgap material, GaAs (Formula presented.) Nx. The microsphere, deposited on top of a GaAs (Formula presented.) Nx:H/GaAs quantum well, is used to generate a photonic nanojet, which removes hydrogen exactly below the microsphere, creating a GaAs (Formula presented.) Nx QD at a predefined distance from the sample surface. Second-order autocorrelation measurements confirm the ability of the QDs obtained with this technique to emit single photons.

Ristori, A., Hamilton, T., Toliopoulos, D., Felici, M., Pettinari, G., Sanguinetti, S., et al. (2021). Photonic Jet Writing of Quantum Dots Self-Aligned to Dielectric Microspheres. ADVANCED QUANTUM TECHNOLOGIES, 4(9) [10.1002/qute.202100045].

Photonic Jet Writing of Quantum Dots Self-Aligned to Dielectric Microspheres

Toliopoulos D.;Sanguinetti S.;
2021

Abstract

Owing to their ability to generate non-classical light states, quantum dots (QDs) are very promising candidates for the large-scale implementation of quantum information technologies. However, the high photon collection efficiency demanded by these technologies may be impossible to reach for “standalone” semiconductor QDs, embedded in a high-refractive index medium. In this work a novel laser writing technique is presented, enabling the direct fabrication of a QD self-aligned—with a precision of ±30 nm—to a dielectric microsphere. The presence of the microsphere leads to an enhancement of the QD luminescence collection by a factor 7.3 ± 0.7 when an objective with 0.7 numerical aperture is employed. This technique exploits the possibility of breaking the N−H bonds in GaAs (Formula presented.) Nx:H by a laser light, obtaining a lower-bandgap material, GaAs (Formula presented.) Nx. The microsphere, deposited on top of a GaAs (Formula presented.) Nx:H/GaAs quantum well, is used to generate a photonic nanojet, which removes hydrogen exactly below the microsphere, creating a GaAs (Formula presented.) Nx QD at a predefined distance from the sample surface. Second-order autocorrelation measurements confirm the ability of the QDs obtained with this technique to emit single photons.
Articolo in rivista - Articolo scientifico
collection enhancement; dilute nitrides; microspheres; photonic jets; site-controlled quantum dots;
English
Hybrid Gold Open Access
Ristori, A., Hamilton, T., Toliopoulos, D., Felici, M., Pettinari, G., Sanguinetti, S., et al. (2021). Photonic Jet Writing of Quantum Dots Self-Aligned to Dielectric Microspheres. ADVANCED QUANTUM TECHNOLOGIES, 4(9) [10.1002/qute.202100045].
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/10281/336758
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