UK team demonstrates tunable alignment of GaAs QD emission
Research led by Oleg Mitrofanov, professor of Terahertz Photonics in University College London (UCL) has demonstrated a new approach for aligning the emission wavelengths of individual GaAs quantum dots using an electrically tunable nonlocal metasurface.
The work 'Voltage-Tunable Nonlocal Metasurface for Enhanced Outcoupling of Emission from Quantum Dots' published in Nano Letters represents a key step towards practical semiconductor platforms for cooperative photon emission.
Cooperative photon emission is a fundamental quantum phenomenon with significant potential for future quantum technologies, but it is difficult to observe in realistic ensembles of semiconductor quantum dots due to natural variability between emitters.
In this study, low-density GaAs quantum dots were embedded within a nonlocal metasurface designed to support extended photonic modes.
The metasurface architecture enables electrical tuning of the emission wavelength while also enhancing photon outcoupling into free space. Variation in the dipole moments of individual quantum dots can be exploited to tune selected pairs into spectral alignment. As a result, two spatially separated quantum dots can be engineered to emit photons at the same wavelength, with strongly improved outcoupling efficiency.
According to the researchers, findings demonstrate a promising route towards scalable, multi-emitter quantum photonic systems based on semiconductor technologies.
