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

Minkyung Jung; Kenji Yoshida; Kidong Park; Xiao-Xiao Zhang; Can Yesilyurt; Zhuo Bin Siu; Mansoor B. A. Jalil; Jinwan Park; Jeunghee Park; Naoto Nagaosa; Jungpil Seo; Kazuhiko Hirakawa

doi:10.1021/acs.nanolett.7b05165

arXiv · 1812.06416

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

Minkyung Jung·Kenji Yoshida·Kidong Park·Xiao-Xiao Zhang·Can Yesilyurt·Zhuo Bin Siu·Mansoor B. A. Jalil·Jinwan Park·Jeunghee Park·Naoto Nagaosa·Jungpil Seo·Kazuhiko Hirakawa

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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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Minkyung Jung, Kenji Yoshida, Kidong Park, Xiao-Xiao Zhang, Can Yesilyurt, Zhuo Bin Siu, Mansoor B. A. Jalil, Jinwan Park, Jeunghee Park, Naoto Nagaosa, Jungpil Seo, Kazuhiko Hirakawa. 2018-12-16. Quantum dots formed in three-dimensional Dirac semimetal Cd$_3$As$_2$ nanowires. https://doi.org/10.1021/acs.nanolett.7b05165

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