  We report on a low-temperature transport study of a single-gate, planar
field-effect device made from a free-standing, wurtzite-crystalline InAs
nanosheet. The nanosheet is grown via molecular beam epitaxy and the
field-effect device is characterized by gate transfer characteristic
measurements and by magnetic field orientation dependent transport
measurements. The measurements show that the device exhibits excellent
electrical properties and the electron transport in the nanosheet is of the
two-dimensional nature. Low-field magnetoconductance measurements are performed
for the device at different gate voltages and temperatures, and the
characteristic transport lengths, such as phase coherent length, spin-orbit
length and mean free path, in the nanosheet are extracted. It is found that the
spin-orbit length in the nanosheet is short, on the order of 150 nm,
demonstrating the presence of strong spin-orbit interaction in the InAs
nanosheet. Our results show that epitaxially grown, free-standing, InAs
nanosheets can serve as an emerging semiconductor nanostructure platform for
applications in spintronics, spin qubits and planar topological quantum
devices.
