Monolithic and hybrid quantum photonic devices (WP2-1)

Host: Toshiba Research Europe Ltd. (TREL)
Supervisor: A. J. Shields, Co-supervision: C. Ford (UCAM)

Cambridge

Bruno Villa

I was born in Colombia and grew up in Bogotá, where I attended a German school. From 2009 to 2015 I studied physics at the University of Stuttgart, where I obtained both my bachelor and master degrees. During the last few years, my research interest has grown towards the fields of nanotechnology and quantum optics. This was encouraged by an exchange semester in Gothenburg (Chalmers), where I learned the fundamentals of micro- and nanofabrication. After this time I worked on my master thesis project, which involved the integration of rare-earth ions doped in inorganic crystals with optical microcavities. I enjoyed the diversity of tasks needed to complete this kind of work, where one can get involved in the whole process, from the modeling through the fabrication to the final measurement and analysis of the data. Now, I’m looking forward to working through these stages for a new project as part of the SAWtrain network.

Objectives

This project aims to acousto-mechanically tune QD excitons into resonance with a localized photonic mode of a microcavity, so that the SAW dynamically controls the Purcell effect. This in turn gives rise to a regulated, deterministic and triggered single-photon (SP) emission. Using state-of-the-art cleanroom fabrication, ESR14-TREL will monolithically integrate etched and planar microcavities containing single QDs on GaAs to assess the optimum microcavity platform for the implementation of this scheme for operation frequencies >1 GHz. ESR14-TREL will build on expertise on SAW tuning of QD excitons at TREL and microcavity tuning of partners PDI and UAU, studying light-emission characteristics (coherence and SP emission purity) using time-correlated SP-counting (TCSPC) spectroscopy.

ESR14-TREL will then transfer electrically active microcavities SP LEDs on to a LiNbO3 substrate for enhanced acousto-mechanical control. This includes device design and fabrication by ELO with ESR9-UAU2. In addition to the spectral tuning, such a hybrid device, jointly realized by two ESRs from the academic and non-academic sector, allows for acoustic regulation of the carrier injection and dynamic programming of the QD charge state at GHz frequencies.

Expected Results

ESR14-TREL will be trained in semiconductor device design, fabrication and characterisation.  The ESR will be taught the use of semiconductor device modelling tools for both electronic and photonic structures. Fabrication training will take place during extended secondments at UCAM and UAU. The ESR will have access to the facilities at TREL for different types of micro- and quantum-optical measurements.

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