ABSTRACT
Semiconductor transistors operate by modulating the charge carrier concentration of a channel material through an electric field coupled by a capacitor. This mechanism is constrained by the fundamental transport physics and material properties of such devices-attenuation of the electric field, and limited mobility and charge carrier density in semiconductor channels. In this work, we demonstrate a new type of transistor that operates through a different mechanism. The channel material is a Weyl semimetal, NbP, whose resistivity is modulated via a magnetic field generated by an integrated superconductor. Due to the exceptionally large electron mobility of this material, which reaches over 1,000,000 cm2/Vs, and the strong magnetoresistive coupling, the transistor can generate significant transconductance amplification at nanowatt levels of power. This type of device can enable new low-power amplifiers, suitable for qubit readout operation in quantum computers.
ABSTRACT
We report measured quantized conductance and quasi-ballistic transport in selectively regrown In0.85Ga0.15As nanowires. Very low parasitic resistances obtained by regrowth techniques allow us to probe the near-intrinsic electrical properties, and we observe several quantized conductance steps at 10 K. We extract a mean free path of 180 ± 40 nm and an effective electron mobility of 3300 ± 300 cm(2)/V·s, both at room temperature, which are among the largest reported values for nanowires of similar dimensions. In addition, optical characterization of the nanowires by photoluminescence and Raman measurement is performed. We find an unintentional increase of indium in the InxGa1-xAs composition relative to the regrown film layer, as well as partial strain relaxation.
