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Updated: Oct 6, 2026

Measurement of Quantum Interference in a Silicon Ring Resonator Photon Source
Published on: April 4, 2017
A spin-photon interface in the telecom C-band with long hole spin dephasing time
Johannes M Michl1, Reza Hekmati2, Mohamed Helal3
1Julius-Maximilians-Universität Würzburg, Physikalisches Institut and Würzburg-Dresden Cluster of Excellence ctd.qmat, Lehrstuhl für Technische Physik, Würzburg, Am Hubland, Deutschland. johannes.michl@uni-wuerzburg.de.
Abstract:
Matter qubits that maintain coherence over extended timescales are essential for many pursued applications in quantum communication and quantum computing. Significant progress has already been made on extending coherence times of spins in semiconductor quantum dots while interfacing them with photons in the near-infrared wavelength range. However, similar results for quantum dots emitting at the telecom range, crucial for many applications, have so far lagged behind. Here, we report on InAs/InAlGaAs quantum dots integrated in a deterministically placed circular Bragg grating emitting at 1.55 μm. We quantify the g-factors of electrons and holes from polarization-resolved measurements of a positive trion in an in-plane magnetic field and study the dynamics of the ground-state hole spin qubit by heralding the spin in two-photon correlation measurements. We quantify the inhomogeneous dephasing times for the electron and hole for various magnetic fields and find a value of ns for the hole spin, for an optimal magnetic field of B = 20 mT.
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