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arXiv · 1311.1801

All-optical sensing of a single-molecule electron spin

A. O. Sushkov·N. Chisholm·I. Lovchinsky·M. Kubo·P. K. Lo·S. D. Bennett·D. Hunger·A. Akimov·R. L. Walsworth·H. Park·M. D. Lukin
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Abstract

We demonstrate an all-optical method for magnetic sensing of individual molecules in ambient conditions at room temperature. Our approach is based on shallow nitrogen-vacancy (NV) centers near the surface of a diamond crystal, which we use to detect single paramagnetic molecules covalently attached to the diamond surface. The manipulation and readout of the NV centers is all-optical and provides a sensitive probe of the magnetic field fluctuations stemming from the dynamics of the electronic spins of the attached molecules. As a specific example, we demonstrate detection of a single paramagnetic molecule containing a gadolinium (Gd$^{3+}$) ion. We confirm single-molecule resolution using optical fluorescence and atomic force microscopy to co-localize one NV center and one Gd$^{3+}$-containing molecule. Possible applications include nanoscale and in vivo magnetic spectroscopy and imaging of individual molecules.

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A. O. Sushkov, N. Chisholm, I. Lovchinsky, M. Kubo, P. K. Lo, S. D. Bennett, D. Hunger, A. Akimov, R. L. Walsworth, H. Park, M. D. Lukin. 2013-11-07. All-optical sensing of a single-molecule electron spin. https://doi.org/10.1021/nl502988n

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