  In conventional metal-oxide semiconductor (CMOS) electronics, the logic state
of a device is set by a gate voltage (VG). The superconducting equivalent of
such effect had remained unknown until it was recently shown that a VG can tune
the superconducting current (supercurrent) flowing through a nanoconstriction
in a superconductor. This gate-controlled supercurrent (GCS) effect can lead to
superconducting logics like CMOS logics, but with lower energy dissipation. The
physical mechanism underlying the GCS effect, however, remains under debate. In
this review article, we illustrate the main mechanisms proposed for the GCS
effect, and the material and device parameters that mostly affect it based on
the evidence reported. We will come to the conclusion that different mechanisms
are at play in the different studies reported so far. We then outline studies
that can help answer open questions on the effect and achieve control over it,
which is key for applications. We finally give insights into the impact that
the GCS effect can have towards high-performance computing with low-energy
dissipation and quantum technologies.
