Institut des
NanoSciences de Paris

Semiconductor quantum dots for integrated quantum optics

Semiconductor-based quantum dots (QD) are ideal systems for implementing robust qubits thanks to their discrete energy levels. Their easy integration in optoelectronic devices allows figuring on realization of quantum logic gates. Quantum dots constitute also efficient single and indistinguishable photon sources for cryptography applications. Our group investigates in particular :

  • Light-matter interaction between single QDs (or two coupled QDs) and different photonic cavities in which the dots are embedded,
  • Dephasing processes in matter, for instance the coupling to a phonon bath or the non-linear interaction between carriers and the nuclear spin bath. Laser pulses can coherently control the defined qubits. The aim is to create efficient spin-photon interfaces by shaping the environment such as the magnetic one, and demonstrate on a long-term entanglement between distant spins. These topics are part of a transverse research topic of INSP on quantum technologies.

Main experimental techniques

The experimental techniques used for achieving coherent control of a qubit, lie on resonant time and spatially resolved optical spectroscopy at low temperature under magnetic field.

  • Coherent spectroscopy for the investigation of quantum systems

The experimental setup consists of several laser sources : two picosecond synchronized Ti-Sa lasers (Coherent), one cw stabilized Ti-Sa (MSquared). The cryogenic system consists of a high mechanical stability closed cycle helium gas cryostat with several optical axes. Microscope objectives and/or optical fibers inside the cryostat are used for focusing the beams on the sample and collect the luminescence. Interferometry setups like Hanbury-Brown-Twiss and Hong-Ou-Mandel allow studying the single photon emission and measure the degree of indistinguishability of the photons.


Recent publications

  • • A. Reigue, F. Lux, L. Monniello, M. Bernard, F. Margaillan, A. Lemaître, J.Iles-Smith, J. Mork, R. Hostein, and V. Voliotis, Probing exciton-photon interaction by two-photon interferences in a resonantly driven quantum dot, Phys. Rev. Lett. 118, 233602 (2017)
  • A. Reigue, M. Bernard, F. Margaillan, A. Lemaître, C. Gomez, C. Ulysse, K. Merghem, R. Hostein, and V. Voliotis, Resonance fluorescence revival in a voltage-controlled semiconductor quantum dot, Appl. Phys. Lett. 112, br>073103 (2018) ;
  • S. Germanis, P. Atkinson, R. Hostein, C. Gourdon, V. Voliotis, A. Lemaître, M. Bernard, F. Margaillan, S. Majrab, and B. Eble, Dark-bright exciton coupling in asymmetric quantum dots, Phys. Rev. B 98, 155303 (2018) ; br>
  • A. Reigue, R. Hostein and V. Voliotis, Resonance fluorescence of a single semiconductor quantum dot : the impact of a fluctuating electrostatic environment, Semicon. Sci. Technol. 34, 113001 (2019) ; br>
  • S.-Y. Shiau, B. Eble, V. Voliotis, and M. Combescot, Photocreation of a dark electron-hole pair in a quantum dot, Phys. Rev. B 101, 161405(R) (2020) br>
  • M. Combescot, V. Voliotis, and S.-Y. Shiau, Fundamental differences between exciton and quantum dot duo, Semiconductor Science and Technology 35 (4), 045013 (2020) br>


• C2N, CNRS Université Paris-Saclay (A. Lemaître, R. Braive) • DTU Photonik, Copenhague, Danemark (J. Mork, J.Iles-Smith) • LP2N, IOGS Bordeaux (P. Lalanne)


• ANR ISQUAD (2018-2022) • DIM SIRTEQ Ile-de-France (2018-2022)