The spectroscopy of the optical centres we study is similar to atomic spectroscopy with the advantage that the centres are fixed in the crystal lattice. Hence, Doppler broadening and spatial diffusion are not present. With the right choice of centres and crystals extremely narrow optical and hyperfine transition line widths are possible, making them ideal for quantum storage and processing applications.
We perform research in a wide range of areas, including:
- Maximizing quantum storage times (the length of time we can store a quantum superposition state). Currently we can store states for over an hour, we aim to increase this to over a day.
- Entangling the quantum states of two crystals. This operation is the basis for a protocol for long-range quantum communication.
- Crystal growth and characterization. We are trying to grow the “perfect crystal”. A crystal with minimal disorder in its lattice structure. Such a crystal will open up to exciting new applications. Currently we are limited by the disorder due to our crystals not being isotopically pure. The next step is to grow isotopically pure samples and characterize the residual disorder in the lattice.
- Quantum planner waveguide devices. To construct a fully integrated quantum processor we are migrating our quantum technologies from bulk crystals to a planner waveguide platform.
- Demonstrating a multi-qubit quantum processor based on RE3+:EuCl3.6D2O.
- Interfacing single rare-earth ions with silicon electronics. This work is done in collaboration with the University of New South Wales and the University of Melbourne. Recently we demonstrated the detection of the optical excitation of a single erbium ion implanted in to a field effect transistor (FET). Optically exciting the ion changes its charge state, changing the electric field inside the transistor, which turns the transistor on. The next step is to detect the nuclear spin state of this single erbium ion.
- Single 'molecules' of nitrogen-vacancy centres in diamond can be used to detecting magnetic fields, electric field, stress and/or temperature and offers many quantum applications at room temperature. Current efforts are directed at better understanding the effects of mechanical stress on the NV centre and designing and fabricating mechanical devices that employ stress to control the centre's quantum properties.
Head of Department