Scanning probe microscopy techniques provide invaluable access to the nanoworld, enabling measurement of local topographic, electronic, optical and magnetic properties depending on the probe used. The emergence of spin-based quantum probes opens up new imaging modalities that can be combined in a single instrument. Here we introduce a “scanning nano-spin ensemble microscope”, in which the microscope probe consists of a small ensemble of optically active quantum spins hosted in a diamond nanocrystal. We illustrate the practicality and versatility of this approach by performing nanoscale imaging of static and fluctuating magnetic fields as well as thermal imaging, at room temperature with typical acquisition times of an hour per image. This opens up new opportunities for nanoscale investigation of a wide variety of materials and phenomena, including in biological settings.
Tetienne JP1,2, Lombard A1,3, Simpson DA4, Ritchie C2, Lu J2, Mulvaney P2, Hollenberg LC1,2,4[expand title=”Show Affiliations”]
- Centre for Quantum Computation and Communication Technology, The University of Melbourne , Melbourne Victoria 3010, Australia.
- Bio21 Institute and School of Chemistry, The University of Melbourne , Melbourne Victoria 3010, Australia.
- Département de Physique, Ecole Normale Supérieure de Cachan , 94235 Cachan, France.
- School of Physics, The University of Melbourne , Melbourne Victoria 3010, Australia.
Quantum sensors based on solid-state spins provide tremendous opportunities in a wide range of fields from basic physics and chemistry to biomedical imaging. However, integrating them into a scanning probe microscope to enable practical, nanoscale quantum imaging is a highly challenging task. Recently, the use of single spins in diamond in conjunction with atomic force microscopy techniques has allowed significant progress toward this goal, but generalization of this approach has so far been impeded by long acquisition times or by the absence of simultaneous topographic information. Here, we report on a scanning quantum probe microscope which solves both issues by employing a nanospin ensemble hosted in a nanodiamond. This approach provides up to an order of magnitude gain in acquisition time while preserving sub-100 nm spatial resolution both for the quantum sensor and topographic images. We demonstrate two applications of this microscope. We first image nanoscale clusters of maghemite particles through both spin resonance spectroscopy and spin relaxometry, under ambient conditions. Our images reveal fast magnetic field fluctuations in addition to a static component, indicating the presence of both superparamagnetic and ferromagnetic particles. We next demonstrate a new imaging modality where the nanospin ensemble is used as a thermometer. We use this technique to map the photo induced heating generated by laser irradiation of a single gold nanoparticle in a fluid environment. This work paves the way toward new applications of quantum probe microscopy such as thermal/magnetic imaging of operating microelectronic devices and magnetic detection of ion channels in cell membranes.Go To Nano Lett