R&D: Reversible Optical Storage Below Diffraction Limit

Nature Nanotechnology has published an article written by Richard Monge, Department of Physics, City College of New York, CUNY, New York, NY, USA, and Graduate Center, CUNY, New York, NY, USA, Tom Delord, Department of Physics, City College of New York, CUNY, New York, NY, USA, and Carlos A. Meriles, Department of Physics, City College of New York, CUNY, New York, NY, USA, and Graduate Center, CUNY, New York, NY, USA.

Abstract: “Colour centres in wide-bandgap semiconductors feature metastable charge states that can be interconverted with the help of optical excitation at select wavelengths. The distinct fluorescence and spin properties in each of these states have been exploited to show storage of classical information in three dimensions, but the memory capacity of these platforms has been thus far limited by optical diffraction. Here we leverage local heterogeneity in the optical transitions of colour centres in diamond (nitrogen vacancies) to demonstrate selective charge state control of individual point defects sharing the same diffraction-limited volume. Further, we apply this approach to dense colour centre ensembles, and show rewritable, multiplexed data storage with an areal density of 21 Gb inch^–2 at cryogenic temperatures. These results highlight the advantages for developing alternative optical storage device concepts that can lead to increased storage capacity and reduced energy consumption per operation.“