Diamonds show promise for spintronic devices

  • Researchers have been exploring the potential for a new technology, called spintronics, that relies on detecting and controlling a particle’s spin.
  • Researchers measured how strongly a charge carrier’s spin interacts with a magnetic field in diamond. This crucial property shows diamond as a promising material for spintronic devices.
  • Diamond is attractive because it would be easier to process and fabricate into spintronic devices than typical semiconductor materials.
  • Conventional quantum devices are based on multiple thin layers of semiconductors, which require an elaborate fabrication process in an ultrahigh vacuum.
  • Diamond is normally an extremely good insulator but when exposed to hydrogen plasma, the diamond incorporates hydrogen atoms into its surface.
  • When a hydrogenated diamond is introduced to moist air, it becomes electrically conductive because a thin layer of water forms on its surface, pulling electrons from the diamond.
  • The missing electrons at the diamond surface behave like positively charged particles, called holes, making the surface conductive. These holes have many of the right properties for spintronics.
  • The most important property is a relativistic effect called spin-orbit coupling, where the spin of a charge carrier interacts with its orbital motion.
  • A strong coupling enables to control the particle’s spin with an electric field. The researchers measured how strongly a hole’s spin interacts with a magnetic field.
  • For this measurement, the researchers applied constant magnetic fields of different strengths parallel to the diamond surface at temperatures below 4 Kelvin. They also simultaneously applied a steadily varying perpendicular field.
  • By monitoring how the electrical resistance of the diamond changed, they determined the g-factor. This quantity could help researchers control spin in future devices using a magnetic field.
  • The coupling strength of carrier spins to electric and magnetic fields lies at the heart of spintronics.
  • Additionally, diamond is transparent, so it can be incorporated into optical devices that operate with visible or ultraviolet light.
  • Nitrogen-vacancy diamonds which contain nitrogen atoms paired with missing carbon atoms in its crystal structure show promise as a quantum bit, or qubit, the basis for quantum information technology. Being able to manipulate spin and use it as a qubit could lead to yet more devices with untapped potential






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