Unveiling the spin-singlet states of two electron-hole pair complexes using two-photon excitation in a GaAs/AlAs quantum dot

S Germanis (1) , P Atkinson (2) , A Bach (1) , R Hostein (1) , R Braive (3) , M Vabre (1) , F Margaillan (1) , M Bernard (1) , V Voliotis (1) , Benoit Eble (1)

1 INSP-E11 - Photons, Magnons et Technologies Quantiques
2 INSP-E8 - Croissance et propriétés de systèmes hybrides en couches minces
3 C2N - Centre de Nanosciences et de Nanotechnologies

We use two-photon excitation to create biexcitonic complexes with two electron-hole pairs in different orbital levels of a GaAs/AlAs quantum dot. In addition to p-shell emission of the biexcitonic triplet states generated by two-photon excitation, we observe additional higher-energy resonances which are a signature of the radiative cascade of two-photon excited singlet states. The detection of these signals obtained in a high excitation regime is made possible by the use of a waveguiding structure in which the quantum dots are inserted, allowing an orthogonal excitation and detection geometry with an excellent laser rejection.

Domaines: Matière Condensée [cond-mat]; Physique Quantique [quant-ph]

S Germanis, P Atkinson, A Bach, R Hostein, R Braive, et al.. Unveiling the spin-singlet states of two electron-hole pair complexes using two-photon excitation in a GaAs/AlAs quantum dot. Physical Review B, 2022, 105 (23), pp.235430. ⟨10.1103/physrevb.105.235430⟩. ⟨hal-03703408⟩