ABSTRACT
Measuring local temperature with a spatial resolution on the order of a few nanometers has a wide range of applications in the semiconductor industry and in material and life sciences. For example, probing temperature on the nanoscale with high precision can potentially be used to detect small, local temperature changes like those caused by chemical reactions or biochemical processes. However, precise nanoscale temperature measurements have not been realized so far owing to the lack of adequate probes. Here we experimentally demonstrate a novel nanoscale temperature sensing technique based on optically detected electron spin resonance in single atomic defects in diamonds. These diamond sensor sizes range from a micrometer down to a few tens of nanometers. We achieve a temperature noise floor of 5 mK/Hz(1/2) for single defects in bulk sensors. Using doped nanodiamonds as sensors the temperature noise floor is 130 mK/Hz(1/2) and accuracies down to 1 mK for nanocrystal sizes and therefore length scales of a few tens of nanometers. This combination of precision and position resolution, combined with the outstanding sensor photostability, should allow the measurement of the heat produced by chemical interactions involving a few or single molecules even in heterogeneous environments like cells.
ABSTRACT
We present a solid state magnetic field imaging technique using a two-dimensional array of spins in diamond. The magnetic sensing spin array is made of nitrogen vacancy (NV) centers created at shallow depths. Their optical response is used for measuring external magnetic fields in close proximity. Optically detected magnetic resonance is read out from a 60 x 60 microm(2) field of view in a multiplexed manner using a charge coupled device camera. We experimentally demonstrate full two-dimensional vector imaging of the magnetic field produced by a pair of current carrying microwires. The presented wide-field NV magnetometer offers, in addition to its high magnetic sensitivity and vector reconstruction, an unprecedented spatiotemporal resolution and functionality at room temperature.
