We demonstrate a controllable p−n junction in a three−dimensional Dirac semimetal (DSM) Cd3As2 nanowire with two recessed bottom gates. The device exhibits four different conductance regimes with gate voltages, the unipolar (n−n and p−p) regime and the bipolar (n−p and n−p) one, where p−n junctions are formed. The conductance in the p−n junction regime decreases drastically when a magnetic field is applied perpendicular to the nanowire, which is due to the suppression of Klein tunneling. In this regime, the device shows quantum dot behavior. On the other hand, clear conductance plateaus are observed in the n−n regime likely owing to the cyclotron motion of carriers at high magnetic fields. Our experiment shows that the ambipolar tunability of DSM nanowires can enable the realization of quantum devices based on quantum dots and electron optics.
@article{arxiv.1909.04353,
title = {Controllable p$-$n junctions in three$-$dimensional Dirac semimetal Cd$_3$As$_2$ nanowires},
author = {Janice Ruth Bayogan and Kidong Park and Zhuo Bin Siu and Sung Jin An and Chiu-Chun Tang and Xiao-Xiao Zhang and Man Suk Song and Jeunghee Park and Mansoor B. A. Jalil and Naoto Nagaosa and Kazuhiko Hirakawa and Christian Schönenberger and Jungpil Seo and Minkyung Jung},
journal= {arXiv preprint arXiv:1909.04353},
year = {2020}
}