近日，清华大学的张昊&何珂及其研究团队取得一项新进展。经过不懈努力，他们实现半导体纳米线的栅极可调谐子带简并。相关研究成果已于2024年6月27日在国际知名学术期刊《美国科学院院刊》上发表。
该研究团队报道了具有近乎对称横截面形状的PbTe纳米线的栅极可调谐子带简并。简并在电子输运中由于没有量子化平台而显露出来。利用双栅极设计，研究人员可以施加电场来提升简并，反映为平台的出现。这种简并及其可调谐提升在以前的纳米线实验中很难观察到，这可能是由于无序性所导致。数值模拟可以定性地捕捉这一观察结果，为未来的应用提供器件参数。
这种退化及其可调谐提升在以前的纳米线实验中很难观察到，可能是由于无序性。数值模拟可以定性地捕捉这一观察结果，为未来的应用揭示器件参数。
据悉，简并和对称在量子系统中有着深刻的关系。
附：英文原文
Title: Gate-tunable subband degeneracy in semiconductor nanowires
Author: Yuhao Wang, Wenyu Song, Zhan Cao , Zehao Yu , Shuai Yang , Zonglin Li, Yichun Gao , Ruidong Li , Fangting Chen, Zuhan Geng, Lining Yang, Jiaye Xu, Zhaoyu Wang, Shan Zhang, Xiao Feng, Tiantian Wang, Yunyi Zang, Lin Li, Runan Shang , Qi-Kun Xue, Dong E Liu, Ke He, Hao Zhang
Issue&Volume: 2024-06-27
Abstract: 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.
Source: https://www.pnas.org/doi/10.1073/pnas.2406884121