Degeneracy and symmetry have a profound relation in quantum systems. Here, we report gate-tunable subband degeneracy in PbTe nanowires with a nearly symmetric cross-sectional shape. The degeneracy is revealed in electron transport by the absence of a quantized plateau. Utilizing a dual gate design, we can apply an electric field to lift the degeneracy, reflected as emergence of the plateau. This degeneracy and its tunable lifting were challenging to observe in previous nanowire experiments, possibly due to disorder. Numerical simulations can qualitatively capture our observation, shedding light on device parameters for future applications.
@article{arxiv.2404.02760,
title = {Gate-tunable subband degeneracy in semiconductor nanowires},
author = {Yuhao Wang and Wenyu Song and Zhan Cao and Zehao Yu and Shuai Yang and Zonglin Li and Yichun Gao and Ruidong Li and Fangting Chen and Zuhan Geng and Lining Yang and Jiaye Xu and Zhaoyu Wang and Shan Zhang and Xiao Feng and Tiantian Wang and Yunyi Zang and Lin Li and Runan Shang and Qi-Kun Xue and Dong E. Liu and Ke He and Hao Zhang},
journal= {arXiv preprint arXiv:2404.02760},
year = {2024}
}