Ultrafast spectroscopy of semiconductor materials for the advancement of quantum technologies

Semiconductors enabled the first quantum revolution, representing the advent of technologies that exploit the properties of quantum-confined electrons. These include integrated circuits, lasers, optical displays, and more, technologies that have had a dramatic impact on the way we live and work. The second quantum revolution promises a whole host of new technologies such as sensors (for medicine, clean-tech, ground surveying), low-noise imaging, secure communications, as well as quantum computing for materials discovery, data management, financial analysis, etc. Technologies in the second quantum revolution would leverage the ability to control additional quantum properties such as spin polarization and quantum entanglement. The realization of such technologies requires advances in our ability to control quantum states and the discovery of new materials with engineerable quantum properties. The Ultrafast Quantum Control Group at Dalhousie uses advanced spectroscopy techniques to probe semiconductor materials of interest for applications in quantum science and technology. The semiconductor materials of interest for our research are self-assembled quantum dots (QDs), transition metal dichalcogenides (TMDs), and hybrid organic-inorganic perovskites (HOIPs). Solid-state emitters are promising for the development of quantum networks and photon sources for quantum cryptography. Our group will advance control strategies for individual and collections of quantum emitters in QDs and strain-localized excitons in TMDs, building upon quantum control techniques utilizing optical pulse shaping developed in our group in recent years. Our extension of optimal control to decoherence suppression for QDs will remove a key barrier to deployment of quantum technologies and we will demonstrate the first coherent optical rotations of localized exciton qubits in TMDs. The HOIPs exhibit extremely strong spin-orbit coupling and offer an unprecedented ability to engineer the spin properties for low-power spintronics or gate-controllable communication between solid-state spin qubits. Our group will carry out the first studies of spin transport in HOIPs, building upon our recent studies of coherent dynamics and spin relaxation in these materials. Our research program in ultrafast spectroscopy and quantum control provides an excellent training ground for highly qualified personnel. Our projects involve custom-built setups at the cutting-edge of optics, imparting an exceptionally high level of technical skills. This prepares our trainees for careers in the photonics and semiconductor industries, with over 400 Canadian companies. Our research program will also provide essential trainees for the emerging quantum sector, for which the urgent need for talent has been identified as one of the primary obstacles to maintaining Canada's leadership position.