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在CoSi中观察具有长费米弧的非传统性费米子
Zhicheng Rao1,2, Hang Li1,2, Tiantian Zhang1,2
1Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing, China.
Nature
|March 22, 2019
概括
研究人员在CoSi中发现了非常规的性费米子,包括自旋-1和电荷-2类型. 这些发现证实了这些奇特粒子的存在, 并为研究它们的特性提供了一个新的平台.
科学领域:
- 凝聚物质物理学
- 量子材料
- 粒子物理学
背景情况:
- 奇拉性是一种在自然界观察到的基本几何性质,在量子场理论中定义为无质粒子.
- 韦尔费米子是一种无质量性费米子,在90年前被预测出来,但仍未经实验证实是基本粒子.
- 在凝聚物质系统中,已经提出了韦尔费米子和其他非传统的性费米子的类型,但直接证据很少.
研究的目的:
- 在凝聚物质系统中实验证实超越标准模型的非传统性费米子的存在.
- 在特定材料中研究这些新奇的性费米子的性能和特征.
- 提供一个新的平台来探索奇拉费米子的物理.
主要方法:
- 使用角度分辨率光辐射光谱 (ARPES) 来探测CoSi的电子结构.
- 用ARPES测量来确定Fermi水平附近的带交叉点.
- 分析的重点是识别非传统的性费米子的特征,例如自旋-1和电荷-2型.
主要成果:
- 在CoSi中在带交叉点实验观察到两种非传统的奇拉费米子,即自旋-1和电荷-2费米子.
- 确定了连接这些性费米子的巨型费米弧,覆盖了整个表面的布里卢恩区域.
- CoSi 呈现出一个独特的配置,单一的奇拉节点被一个大的动量空间分开,导致极长的表面费米弧.
结论:
- 这项研究提供了CoSi中非传统性费米子 (旋转-1和电荷-2) 的第一个直接实验证据.
- 由于其特定的晶体对称性和由此产生的晶体节点的巨大分离,CoSi作为研究性费米子的独特平台.
- 这些发现为探索性费米子的基本物理和潜在应用开辟了新的途径.
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