Photonics and coherence of spin – Spin relaxation and decoherence in semiconductor nano-heterostructures

List of members


Internships and jobs





Spin relaxation and spin coherence of the electronic spin bound to donors


  • Permanent members: Frédérick Bernardot, Maria Chamarro, Christophe Testelin
  • PhD student: Guillaume Lagüe

Spin relaxation time, T1, and spin coherence time, T2, are key properties of quantum bit (qubit) candidates. We investigated T1 and T2 times of the electron bound to donors immerged in a 2D material (CdTe quantum well) by using a pump-probe technique: the photo-induced Faraday rotation.


Recent publications

  • We calculated the exchange energy of a pair of donor-bound electrons placed in the middle of an infinite quantum well (QW) and obtained universal curves valid for any inter-donor distance and for any QW thickness. This tool allows, in particular, to calculate T1 near the insulator-metal transition in QWs made of widely used II-VI and III-V direct-band-gap materials. PRB, 98, 195308, (2018)

Caption: Individual I donor immersed in a CdTe quantum well. Temporal evolution of the photo-induced Faraday Rotation signal.

  • T1 dependence on the doping concentration at low temperature follows a non-monotonous behavior in the insulator regime, which is successfully explained by the interplay of hyperfine interaction and anisotropic exchange interaction. PRB, 99, 235301, (2019)
  • The T1 behaviour was also studied with varying temperature. PRB, 100, 205305, (2019)
  • T1 behaviour versus longitudinal magnetic field. We evidenced a new mechanism of relaxation associated to the electron hopping to neighboring donor sites at moderate magnetic field. PRB, to be published 2020


  • Institute of Physics, Polish Academy of Sciences, Warsaw, Poland


Photo-spintronics with perovskite materials


  • Permanent members: Thierry Barisien, Frédérick Bernardot, Maria Chamarro, Laurent Legrand, Christophe Testelin
  • Post-doctoral fellow: Guadalupe Garcia-Arellano

We study the coherent dynamics of carriers spins, so far poorly studied, in hybrid or completely inorganic perovskite-based materials to obtain a fundamental understanding of spin-dependent physics. We chose to focus our study on perovskites based on lead and a halide, of formula APbX3 with A = organic group and X = Cl, Br, I. because these compounds offer the possibility of tuning the bandgap and the spin-orbit coupling by means of a simple chemical substitution.

Caption: Coherent evolution of the electronic spin in MAPbI3 bulk crystals. Inset: Halide Perovskite typical crystal structure


  • OCN Team (INSP) ;
  •  Laboratoire Lumière Matière et Interfaces (LuMIn Université Paris Saclay) ;
  • GEMAC, Université de Versailles Saint-Quentin en Yvelines.