Quantum dots formed in three-dimensional Dirac semimetal Cd${}_3$As${}_2$ nanowires

Abstract

We demonstrate quantum dot (QD) formation in three-dimensional Dirac semimetal Cd${}_3$As${}_2$ nanowires using two electrostatically tuned p$-$n junctions with a gate and magnetic fields. The linear conductance measured as a function of gate voltage under high magnetic fields is strongly suppressed at the Dirac point close to zero conductance, showing strong conductance oscillations. Remarkably, in this regime, the Cd${}_3$As${}_2$ nanowire device exhibits Coulomb diamond features, indicating that a clean single QD forms in the Dirac semimetal nanowire. Our results show that a p$-$type QD can be formed between two n$-$type leads underneath metal contacts in the nanowire by applying gate voltages under strong magnetic fields. Analysis of the quantum confinement in the gapless band structure confirms that p$-$n junctions formed between the p$-$type QD and two neighboring n$-$type leads under high magnetic fields behave as resistive tunnel barriers due to cyclotron motion, resulting in the suppression of Klein tunneling. The p$-$type QD with magnetic field-induced confinement shows a single hole filling. Our results will open up a route to quantum devices such as QDs or quantum point contacts based on Dirac and Weyl semimetals.

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Cited by in corpus (6)

• Progress in epitaxial thin-film Na3Bi as a topological electronic material
• Generation of strain-induced pseudo-magnetic field in a doped type-II Weyl semimetal
• Photonic Dirac Nodal Line Semimetals Realized by Hyper-crystal
• AC Josephson effect in a gate-tunable Cd${}_3$As${}_2$ nanowire superconducting weak link
• Controllable p$-$n junctions in three$-$dimensional Dirac semimetal Cd${}_3$As${}_2$ nanowires
• Electronic scattering, focusing, and resonance by a spherical barrier in Weyl semimetals