Subcategory: Physics (not Nanoscience)
Richard G. Monge - The CUNY (City University of New York) Graduate Center, CUNY The City College of New York, NY
Co-Author(s): Co-Author(s): Artur Lozovoi, Carlos A. Meriles, The City College of New York, NY.
The Nitrogen-Vacancy (NV) centers in diamond are robust color centers whose quantum nature allows for the optical detection of its magnetic resonance. The electronic structure of this defect makes it possible to spin-initialize and manipulate the electronic spin via microwave and laser pulses. It is this same electronic structure that allows the optical detection of its spin by monitoring its change in fluorescence. The NV has been shown to serve as a powerful magnetic field, electric field, strain, and temperature sensor1 using the detected shift and/or splitting of these magnetic resonance lines2. Nanoscale magnetometry via the NV Center in diamond has emerged as a promising approach to sense spin complexes. NV-based scanning probe microscopy has used a single NV center for magnetic sensing with nanometer precision. Due to the weak thermal dependence of the magnetic resonance lines3, NV-based nanoscale thermometry?s sensitivity is relatively low. Attempts to circumvent this insensitivity include detecting temperature via the magnetization of magnetic nanoparticles attached to bulk diamond4. Here, we have employed NV-based scanning probe microscopy by using a non-contact atomic force microscope (AFM) probe tip with a nanodiamond at its apex. We demonstrate a novel way to increase temperature sensitivity by monitoring the longitudinal spin relaxation T1 of NV centers on the AFM tip. This is achieved by applying a static magnetic field at ~514 Gauss and inducing cross-relaxation between the NV Center and neighboring nitrogen (P1) centers. At this static magnetic field, a steep change in T1 translates into an increase in temperature sensitivity. Future research plans include using the NV?s on the AFM probe to monitor paramagnetic impurities in superconducting circuits at low temperatures and locate hotspots by monitoring T1 times. References: 1. Laraoui, A. et al. Imaging thermal conductivity with nanoscale resolution using a scanning spin probe. Nat. Commun. (2015). doi:10.1038/ncomms9954 2. Acosta, V. & Hemmer, P. Nitrogen-vacancy centers: Physics and applications. MRS Bull. (2013). doi:10.1557/mrs.2013.18 3. Acosta, V. M. et al. Temperature dependence of the nitrogen-vacancy magnetic resonance in diamond. Phys. Rev. Lett. (2010). doi:10.1103/PhysRevLett.104.070801 4. Wang, N. et al. Magnetic Criticality Enhanced Hybrid Nanodiamond Thermometer under Ambient Conditions. Phys. Rev. X (2018). doi:10.1103/PhysRevX.8.011042 .1103/PhysRevX.8.011042
Funder Acknowledgement(s): Acknowledge support from CREST IDEALS.
Faculty Advisor: Carlos Meriles, email@example.com
Role: I performed all the experiments with the help and guidance of post doctoral fellow Artur Lozovoi and Professor Carlos Meriles. This includes the protocol of capturing NV's on an AFM tip and performing pulsed spin measurements on the NV's for quantum sensing.