Research

Spintronics

Spintronics is a branch of physics and nanoscience concerned with the storage and transfer of information by means of electron spins in addition to electron charge as in conventional electronics. The birth of spintronics can be traced to basic research on nanoscale ferromagnet/normal-metal multilayers in late 1980s, as recognized by the Nobel Prize in Physics 2007 awarded for the discovery of giant magnetoresistance (GMR). The GMR phenomenon also exemplifies one of the fastest transfers of basic research into applications where in less then ten years since its discovery it has revolutionized information storage technologies by enabling 100 times increase in hard disk storage capacity.

Unlike early non-coherent spintronics phenomena (such as GMR), the major themes of the second-generation spintronics are exploiting quantum-coherent spin states where spin component persists in the direction transverse to external or effective internal magnetic fields. Examples of such phenomena in metal spintronics are spin transfer torque (spin current of large enough density injected into a ferromagnetic layer either switches its magnetization from one static configuration to another or generates a dynamical situation with steady-state precessing magnetization) and spin pumping (moving magnetization generates pure spin current with no applied bias voltage and accompanying net charge current). In semiconductor spintronics recent second-generation experiments have succed in: transporting coherent precessing spins across 100 micron thick silicon wafers; detecting direct and inverse spin Hall effect; and manipulating localized coherent spins as building blocks of futuristic solid-state-based quantum computers. A major teme of second-generation spintronics is exploration of various quantum phenomena that can be exploited to generate pure spin currents as a situation with no net charge current.

Our spintronics projects are focused on:

• spin pumping and related time-dependent spin-transport phenomena,
• spin-transfer torque,
• spin Hall effect.

See also our Publications page and Spintronics page at the Department of Physics & Astronomy Website.