  Spin momentum locking is a key feature of the topological surface state,
which plays an important role in spintronics. The electrical detection of
current-induced spin polarization protected by the spin momentum locking in
non-magnetic systems provides a new platform for developing spintronics while
previous studies were mostly based on magnetic materials. In this study, the
spin transport measurement of Dirac semimetal Cd3As2 was studied by the
three-terminal geometry, and a hysteresis loop signal with high resistance and
low resistance state was observed. The hysteresis was reversed by reversing the
current direction, which illustrates the spin-momentum locking feature of
Cd3As2. Furthermore, we realized the on-off states of the spin signals through
electric modulation of the Fermi arc via the three-terminal configuration,
which enables the great potential of Cd3As2 in spin field-effect transistors.
