  We report the operation of a field-effect transistor based on a single InAs
nanowire gated by an ionic liquid. Liquid gating yields very efficient carrier
modulation with a transconductance value thirty time larger than standard back
gating with the SiO2 /Si++ substrate. Thanks to this wide modulation we show
the controlled evolution from semiconductor to metallic-like behavior in the
nanowire. This work provides the first systematic study of ionic-liquid gating
in electronic devices based on individual III-V semiconductor nanowires: we
argue this architecture opens the way to a wide range of fundamental and
applied studies from the phase-transitions to bioelectronics.
