Spin Transport in Room-Temperature Germanium

Finding materials that can sustain a spin-polarized current is key for further developing the field of spintronics. Germanium is a promising material because it has a higher carrier mobility than silicon, which could allow for faster devices, but spin transport in germanium has so far only been clearly demonstrated at low temperature (below 225K). A new room-temperature experiment shows that spin currents can travel more than half a micrometer along a thin slab of doped germanium.

Spintronics—in which electron spin is used to carry information—could revolutionize the electronics industry by increasing computation speed and lowering power consumption. But in most materials, scattering and fluctuating magnetic fields can rapidly flip spins, causing the loss of spin polarization and the associated information. Germanium has a particular lattice symmetry that should reduce much of this spin relaxation. However, since germanium is nonmagnetic, measuring spin transport is not easy because spin currents have to be created in a magnetic material and injected into germanium.