Southwest Quantum Information and Technology

Imaging individual 25-nm superparamagnetic nanoparticles using diamond magnetic microscopy

Presenting Author: Abdelghani Laraoui, University of New Mexico CHTM
Contributing Author(s): Nazanin Mosavian, Janis Smits, Ilja Fescenko, Victor Acosta University of New Mexico, Dept. of Physics and Center for High Technology Materials Andrey Jarmola ODMR Technologies, El Cerrito, CA, and University of California-Berkeley, Dept of Physics.

Nitrogen-vacancy (NV) centers in diamond are presently been investigated for quantum information processing and as quantum sensors for studying magnetism at the nanometer scale. This is facilitated by their unique properties, including the long electron spin coherence time (exceeding one millisecond) and superb photostability at room temperature. The goal of this research is to develop new strategies based on NV centers for high throughput, high spatio-temporal resolution characterization of individual magnetic nanoparticles (MNPs) for biomedical imaging and nanotechnology applications. We doped a diamond chip with a near-surface (<200 nm) layer of NV centers and used it to perform wide field magneto-optical microscopy by optically detecting the NV magnetic resonance frequencies. We measured the static and dynamic magnetic properties of 15-25 nm individual superparamagnetic nanoparticles and correlated them with their morphology determined from atomic force and transmission electron microscopy. The images reveal magnetic dipole field patterns (> 20 uT) from small clusters of MNPs as well as weaker signatures (~8 uT) from individual MNPs. This study will provide a fundamental understanding of the effect of size, surface structure, and inter-particle dipolar interactions on MNP magnetic properties.

(Session 5 : Thursday from 5:00pm - 7:00 pm)