Radio-frequency stress-induced modulation of CdTe/ZnTe quantum dots

V. Tiwari (1) , K. Makita (2) , M. Arino (2) , M. Morita (2) , T. Crozes (3) , E. Bellet-Amalric (4) , S. Kuroda (2) , H. Boukari (1) , L. Besombes (1)

1 NEEL - NPSC - Nanophysique et Semiconducteurs
2 Université de Tsukuba = University of Tsukuba
3 NEEL - Nanofab - Nanofabrication
4 NPSC - Nanophysique et Semiconducteurs

We demonstrate radio-frequency tuning of the energy of individual CdTe/ZnTe quantum dots (QDs) by Surface Acoustic Waves (SAWs). Despite the very weak piezoelectric coefficient of ZnTe, SAW in the GHz range can be launched on a ZnTe surface using interdigitated transducers deposited on a c-axis oriented ZnO layer grown on ZnTe containing CdTe QDs. The photoluminescence (PL) of individual QDs is used as a nanometer-scale sensor of the acoustic strain field. The energy of QDs is modulated by SAW in the GHz range and leads to characteristic broadening of time-integrated PL spectra. The dynamic modulation of the QD PL energy can also be detected in the time domain using phase-locked time domain spectroscopy. This technique is in particular used for monitoring complex local acoustic fields resulting from the superposition of two or more SAW pulses in a cavity. Under magnetic field, the dynamic spectral tuning of a single QD by SAW can be used to generate single photons with alternating circular polarization controlled in the GHz range.

Domaines: Autre [cond-mat.other]

V. Tiwari, K. Makita, M. Arino, M. Morita, T. Crozes, et al.. Radio-frequency stress-induced modulation of CdTe/ZnTe quantum dots. Journal of Applied Physics, 2020, 127 (23), pp.234303. ⟨10.1063/5.0011124⟩. ⟨hal-02874811⟩