Phonon-Assisted Transport and Hole–Phonon Coupling in GaAs Double Quantum Dots

Hole–phonon interactions play an important role in transport and decoherence processes in semiconductor quantum dots. Here we investigate hole–phonon coupling in a gate-defined GaAs double quantum dot integrated with a quantum point contact charge sensor. Under finite source–drain bias, pronounced oscillatory stripe patterns appear near specific charge transition regions in the charge stability diagram. We attribute these oscillations to phonon emission during inelastic interdot tunneling. A theoretical model including piezoelectric hole–phonon coupling reproduces the observed patterns. Furthermore, our analysis shows that the oscillations emerge only in particular charge configurations. Our results provide direct insight into phonon-assisted transport and coherent hole–phonon interactions in semiconductor quantum dots.