  Superconducting field-effect transitor (SuFET) and Josephson field-effect
transistor (JoFET) technologies take advantage of electric field induced
control of charge carrier concentration in order to modulate the channel
superconducting properties. Despite field-effect is believed to be unaffective
for superconducting metals, recent experiments showed electric field dependent
modulation of the critical current (IC) in a fully metallic transistor. Yet,
the grounding mechanism of this phenomenon is not completely understood. Here,
we show the experimental realization of Ti-based Dayem bridge field-effect
transistors (DB-FETs) able to control IC of the superconducting channel. Our
easy fabrication process DB-FETs show symmetric full suppression of IC for an
applied critical gate voltage as low as VCG~+-8V at temperatures reaching about
the 85% of the record critical temperature TC~550mK for titanium. The
gate-independent TC and normal state resistance (RN) coupled with the increase
of resistance in the supercoducting state (RS) for gate voltages close to the
critical value (VCG) suggest the creation of field-effect induced metallic
puddles in the superconducting sea. Our devices show extremely high values of
transconductance (gMAXm~15uA/V at VG~+-6.5V) and variations of Josephson
kinetic inductance (LK) with VG of two orders of magnitude. Therefore, the
DB-FET appears as an ideal candidate for the realization of superconducting
electronics, superconducting qubits, tunable interferometers as well as photon
detectors.
