  Spintronic devices as alternatives to traditional semiconductor-based
electronic devices attract considerable interest as they offer zero quiescent
power, built-in memory, scalability, and reconfigurability. To realize
spintronic logic gates for practical use, a complementary logic operation is
essential but still missing despite a recent progress in spin-based logic
devices. Here, we report the development of a complementary spin logic device
using electric-field controlled spin-orbit torque (SOT) switching. In heavy
metal/ferromagnet/oxide structures, the critical current for SOT-induced
switching of perpendicular magnetization is efficiently modulated by an
electric field via voltage-controlled magnetic anisotropy (VCMA) effect in a
non-volatile manner. Moreover, the polarity of the VCMA is tuned by the
modification of oxidation state at the ferromagnet/oxide interface. This allows
us to fabricate both n-type and p-type spin logic devices and to enable a
complementary logic operation, paving the way for the development of
non-volatile and reconfigurable logic devices.
