Research > Faculty Projects

CAREER: A 'holistic' approach toward scalable quantum optical networks in semiconductors

Principal Investigator
Kai-Mei Fu


National Science Foundation

Award Period
08/15/2012 - 07/31/2017

In this work we investigate a new qubit system ideal for realizing an optically connected quantum network: single acceptor-bound holes (A0) in III-V quantum wells (QW). This system has the potential to combine millisecond long spin coherence times with strong, homogeneous optical transitions in a nanofabrication-ready material. Far-field super-resolution optical techniques will be developed in order to isolate single impurity-bound excitons (A0X), with the goal of reaching optical resolutions on the order of the effective mass Bohr radius. These techniques will be combined with ultrafast optical spin control to study the effect of QW confinement and nearby surfaces on the optical and spin coherence properties of the A0-A0X system. Knowledge gained from these studies will guide research on integrating single impurities into optical nanocavities. The longer term goal of the project is to realize optically-connected few qubit devices in a scalable architecture.

A quantum information network based on photons and spins would enable quantum simulation, secure long-distance quantum communication, and quantum computation. In this work we study single impurities in semiconductors as potential quantum bits for such a network. Nanoscale low temperature imaging techniques will be developed to isolate single impurities. Ultrafast optical techniques will be used to study the impurity qubit lifetime. The longer term goal of the project is to realize a few qubit network in which spins are connected through on-chip optical devices. The research program will involve, teach, and train undergraduates, graduate students, and postdoctoral associates in experimental physics, quantum optics, and nanoscience. In addition to training undergraduate students, graduate students and postdocs in quantum optics, physics and nanotechnology, an integral part of the broader impact of this program includes community outreach at a local elementary school. University of Washington physics and electrical engineering students, working closely with a Sansislo elementary school science teacher, are engaging 4th-5th grade students in weekly science activites aimed at understanding light.

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