Dynamical criticality of single magnetic nanoparticles near phase transition

POSTER

Abstract

Understanding the critical phenomena of magnetic nanoparticles (MNPs) is crucial to both fundamental physics and the state-of-the-art technology. NV centers in diamond simultaneously provide nanoscale spatial resolution, high magnetometry sensitivity and large temporal dynamic range under ambient conditions, and therefore are ideal quantum sensors for studying the dynamical criticality of MNPs. We developed a broadband sensing protocol with NV center spins to study the magnetic fluctuations of single magnetic nanoparticles near the critical point. We observed paramagnetic and superparamagnetic fluctuations of the MNP and extracted the correlation time and amplitude of the magnetic fluctuations.

* This work is supported by Hong Kong RGC Theme-Based Research Scheme project T45-406/23-R.

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Presenters

  • Xianfeng Wang

    Chinese University of Hong Kong

Authors

  • Xianfeng Wang

    Chinese University of Hong Kong

  • Ning Wang

    Chinese University of Hong Kong

  • Weng Hang Leong

    Chinese University of Hong Kong

  • Xi Feng

    Chinese University of Hong Kong

  • Chufeng Liu

    Chinese University of Hong Kong

  • Jingwei Fan

    Chinese University of Hong Kong

  • Amit Finkler

    Weizmann Institute of Science

  • Andrej Denisenko

    University of Stuttgart

  • Jörg Wrachtrup

    University of Stuttgart

  • Quan Li

    Chinese University of Hong Kong

  • Renbao Liu

    Chinese University of Hong Kong