Magnetism and Superconductivity Group

Our Research

Nuclear Magnetic Resonance Microscopy and Spectroscopy

  • Conventional nuclear magnetic resonance (NMR) spectroscopy to study spin dynamics
  • One of the few groups worldwide to be pioneering the new technique of NMR force microscopy (NMRFM). Where one couples the nuclear moments of a sample to micro-oscillators and detects motion with fiber-optic interferometry
  • Applied to study physics of:
    • Polymer films
    • Metal hydride films
    • Individual cell microscopy
    • NMR of microcrystals
  • Ultimate goal is for single nuclear spin detection
  • Applications in molecular biology, quantum computation, and subsurface characterization

Dynamics of Ferromagnets

  • Electron-beam evaporation of thin magnetic films, magnetic dots, and multilayers onto oscillators
  • Domain wall motion: study of interface depinning, hysteresis, reproductibity, and criticality (self-organized or otherwise)
  • Study of effects of interface topography and reduced dimensionality on ultrathin film and multilayer magnetism

High-Q Oscillator Experiment

Probe fundamental phenomena at force sensitivities of 3x10-18 N at 0.3 K and displacements of 10-4 nm. For example:

  • Direct measurement of transverse forces on moving vortices (the Magnus effect)
  • "Intrinsic" pinning of magnetic vortices due to spatial variations of the superconducting order parameter

High Temperature Superconducting Materials

In-house fabrication of supercondunducting materials using several processes:

  • Crystal growth of copper-oxide materials
  • Synthesis by novel routes (high pressure; low temperature)
These materials are tested for anisotropy, vortex dynamics, magnetoelectric properties using:
  • SQUID magnetometry
  • Specific heat measurements
  • Transport measurements (magnetoresistance, Hall effect, etc.)
  • High pressure systems
  • Nuclear magnetic resonance

Novel Charge States of Oxide Interfaces

Pulsed laser deposition of epitaxial oxide films used in studying interfaces with regards to:

  • 2D quantum transport
  • Effects of systematic variation of interface strain and intrinsic doping

Optically Switchable Metal Hydride Films

Investigation into the physics behind the optical switching properties of metal-hydride thin films:

  • Diffusion
  • Substrate strain ("superdiffusion")
  • Alloy composition
  • Metal/insulator transition
  • Cooperative displacements; electron correlations