Michiel Sprik
Journal of Physics Condensed Matter
We have measured the transport properties in field effect transistors that incorporate underdoped YBa2Cu3O7-δ as the conducting channel material. Once fabricated, devices are deoxygenated in argon gas at temperatures 250-350 °C. The devices are then vapor cooled above a bath of liquid helium and two-wire resistivity measurements are made between room temperature and 4.2 K. For zero applied gate voltage (Vg) and in sufficiently underdoped devices we observe two-dimensional (2D) Mott variable range hopping (VRH). As we remove more oxygen, we observe a transition to Efros-Shklovskii VRH. For Vg<O we generally observe 2D Mott VRH.
Michiel Sprik
Journal of Physics Condensed Matter
J.K. Gimzewski, T.A. Jung, et al.
Surface Science
R.D. Murphy, R.O. Watts
Journal of Low Temperature Physics
U. Wieser, U. Kunze, et al.
Physica E: Low-Dimensional Systems and Nanostructures