USC USC Takahashi Group


Supported by

Anton B. Burg Foundation

Zumberge Research Fund

Contact information

Department of Chemistry
840 Downey Way
University of Southern California
Los Angeles, CA 90089-0744

Last modified: 09/12/2015


Research topics

Our current topics of research are following.

Nanoscience and nanomaterials

Investigating nanomagnetism, single spin dynamics, quanutm coherence and surface/defect effects to understand/control nano-scale phenomena.

Nitrogen-vacancy center in diamond and nanodiamond

A nitrogen-vancay defect center in diamond and nanodiamond is a promising candidate for applicaitons of quantum computing and spin tronics devices. We investigate single spin dynamics of a NV center and quantum coherence in diamond and nanodiamond using our novel MR systems.

Figure. Fluorescence image of a single spin NV center in diamond.

Surface chemistry of nanodiamond

Diamond is a highly bio-compatible and promising material for living-cell imaging, drag delivery and magnetic/electric/thermal sensing applications. We develop surface chemistry techniques for diamond.

Figure. Click chemistry approach to funtionalize the surface of nanodiamond.

Molecular nanomagnets

Molecular magnets are nano-sized magnetic molecules and an attractive testbed for basic science and applications to high-density magnetic storage and spintronics devices because their magnetic properties can be easily tuned with highly flexible chemical synthesis of moloecular magnets. We investigate properties of magnetic storage memory time and quantum coherence in molecular magnets.

Figure. EPR analysis of Fe8 molecular magnets.

Instrumentation development

Developing novel magnetic resonance techniques.

Single-molecule magnetic resonance system

Magnetic resonance (MR), such as nuclear magnetic resonance (NMR) and electron paramagnetic resonance (EPR), can probe the local structure and dynamic properties of various systems, making them among the most powerful and versatile analytical methods. However, their intrinsically low sensitivity precludes MR analyses of samples with very small volumes; e.g., more than 1010 electron spins are typically required to observe EPR signals at room temperature. We are aiming to improve the current limits of MR sensitivity down to the level of single spin.

Figure. Microscope component in the single MR system.

High-frequency/high-field EPR spectrometer (0-12.1 Tesla and 107-120/215-240 GHz)

Pulsed EPR enables measurements which are not possible with continuous wave (cw) spectroscopy, such as determining structure of fast trasient states and measuring intrinsic spin relaxation (decoherence) time. We have recently developed a unique high-frequency/high-field insterument for pulsed EPR experiments, enabling: 1) finer spectral resolution, 2) better absolute sensitivity with higher degree of spin polarization, 3) improved time resolution.

Figure. High-ferquency/high-field pulsed/cw EPR system in our lab.