Work

Measurement-induced back-action in a QD-based coherent spin-photon interface

Year: 2025

Type: article

Abstract: Spin-photon interfaces constitute promising candidates for the development of stationary nodes used as photon receivers, for quantum communication, and distributed quantum computing. Towards these applications, an important step is the control of the back-action induced on a single spin qubit following the measurement of a scattered photon. Here, we demonstrate and quantify the quantum back-action effect on an electron spin in a semiconductor quantum dot, triggered by the detection of a single reflected photon. Through a time-resolved polarization tomography approach, we show that the induced population and coherence of the spin state can be tuned by the chosen polarization basis of the measurement. We demonstrate that the spin dynamics is mapped onto the dynamics of the polarization state of reflected photons. This allows inferring all the relevant spin dynamics timescales, including precession, decoherence, and relaxation times, using a single tomography protocol.

Source: Optica Quantum

DOI: 10.1364/opticaq.578115