First high-resolution spectroscopy of single rare-earth ions in a crystal

01.01.2014, 00:00

Newsletter 7

Solid-state emitters with atom-like optical and magnetic transitions are highly desirable for efficient and scalable quantum state engineering and information processing. Quantum dots, colour centres and embedded impurities have attracted a great deal of attention in this context, but influences from the surrounding matrix continue to pose challenges on the degree of attainable coherence in each system. An alternative solid-state platform builds on the optical detection and spectroscopy of single rare earth ions via their 4f intrashell transitions, which are well shielded from their environment. This leads, however, to long fluorescence lifetimes and thus weak emission, with the result that detection of rare earth ions through 4f transitions has proven to be elusive for more than two decades. By combining cryogenic high-resolution laser spectroscopy with fluorescence microscopy, we have now succeeded in spectrally selecting and spatially resolving individual praseodymium ions. The sharp lines in the figure display the fluorescence of individual ions within the inhomogeneous absorption spectrum of the sample. Access to the hyperfine levels via narrow-band lasers also allows us to prepare and read out information in single ions. Our results present a new solid-state system for single-emitter quantum optics.

Contact: tobias.utikal(at)mpl.mpg(dot)de
Group: Sandoghdar Division
Reference:  T. Utikal et al., Nature Communications 5, 3627 (2014).