  Charge-based field-effect transistors (FETs) greatly suffer from unavoidable
carrier scattering and heat dissipation. In analogy to valley degree of freedom
in semiconductors, chiral anomaly current in Weyl/Dirac semimetals is
theoretically predicted to be nearly non-dissipative over long distances, but
still lacks experimental ways to efficiently control its transport. Here we
demonstrate field-effect chirality devices with Dirac semimetal PtSe2, in which
its Fermi level is close to the Dirac point in conduction band owing to
intrinsic defects. The chiral anomaly is further corroborated with nonlocal
valley transport measurement, which can also be effectively modulated by
external fields, showing robust nonlocal valley transport with micrometer
diffusion length. Similar to charge-based FETs, the chiral conductivity in
PtSe2 devices can be modulated by electrostatic gating with an ON/OFF ratio
more than 103. We also demonstrate basic logic functions in the devices with
electric and magnetic fields as input signals.
