Magnetoresistive-coupled transistor using the Weyl semimetal NbP.

Rocchino, Lorenzo; Balduini, Federico; Schmid, Heinz; Molinari, Alan; Luisier, Mathieu; Süß, Vicky; Felser, Claudia; Gotsmann, Bernd et al. · Nat Commun · 2024

basic_science · Level V

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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 cm<sup>2</sup>/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.