  Electric gating can strongly modulate a wide variety of physical properties
in semiconductors and insulators, such as significant changes of conductivity
in silicon, appearance of superconductivity in SrTiO3, the
paramagnet-ferromagnet transition in (In,Mn)As and so on. The key to such
modulation is charge accumulation in solids. Thus, it has been believed that
such modulation is out of reach for conventional metals where the number of
carriers is too large. However, success in tuning the Curie temperature of
ultrathin cobalt gave hope of finally achieving such degree of control even in
metallic materials. Here, we show reversible modulation of up to two orders of
magnitude of the inverse spin Hall effect - a phenomenon that governs
interconversion between spin and charge currents - in ultrathin platinum.
Spin-to-charge conversion enables the generation and use of electric and spin
currents in the same device, which is crucial for the future of spintronics and
electronics.
