Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe

HL: Fachverband Halbleiterphysik

HL 18: Nanomechanical systems (joint session HL/TT)

HL 18.5: Vortrag

Dienstag, 10. März 2026, 11:15–11:30, POT/0051

Probing Mechanical Nonlinearities with Quantum Dots — •Noah Spitzner, Jona Richter, Emeline Denise Sophie Nysten, Matthias Weiß, and Hubert Krenner — Universität Münster, Münster, Germany

The coupling of quantum dots to mechanical resonances is a well-established approach to investigate the behaviour of mechanical resonators and crystals. Within that approach, the quantum dots (QDs) act as point-like sensors sensitive to dynamical changes to their lattice constant. Vibrations in the host structure modulate the emission energy of the quantum dot, enabling readout of mechanical modes via ultrafast optical detectors. In our hybrid structures, mechanical excitation is achieved by integrating the QD-membrane onto a lithium niobate substrate equipped with finger-like electrodes called interdigitated transducers (IDTs). Applying a radio-frequency (RF) signal to the IDTs generates surface acoustic waves, which propagate on the surface of the substrate, coupling to quantum dots in their path.

This hybrid platform was taken a step further by structuring the QD-membrane into rings hosting mechanical resonances. Frequency sweeps of the RF signal applied to the IDT revealed sharp resonances in the emission-energy modulation exclusively for the quantum dots located within the rings. Interestingly, the resonances appear over a large region of SAW frequencies from 200 MHz to 900 MHz. Moreover, we detect clear signatures of a nonlinear mechanical response e.g. asymmetric lineshapes in the time-modulated optical signal of the QD when the external drive by the IDT is increased.

Keywords: Surface Acoustic Waves; Quantum Dots; Mechanical Nonlinearities