  The ionic-liquid-gating technique can be applied to the search for novel
physical phenomena at low temperatures because of its wide controllability of
the charge carrier density. Ionic-liquid gated field-effect transistors are
often fragile upon cooling, however, because of the large difference between
the thermal expansion coefficients of frozen ionic liquids and solid target
materials. In this paper, we provide a practical technique for setting up
ionic-liquid-gated field-effect transistors for low-temperature measurements.
It allows stable measurements and reduces the electronic inhomogeneity by
reducing the shear strain generated in frozen ionic liquid.
