在KTaO3 (111) 接口上进行二维超导和异构传输
Changjiang Liu1, Xi Yan2,3,4, Dafei Jin5
1Materials Science Division, Argonne National Laboratory, Lemont, IL 60439, USA. anand@anl.gov changjiang.liu@anl.gov.
概括
在以111为导向的KTaO3接口的电子气体中出现超导,达到2.2克尔文. 在甲 (KTaO3) 系统中发现的这种发现明显高于之前在类似材料中观察到的.
科学领域:
- 凝聚物质物理学
- 材料科学
- 量子材料
背景情况:
- 不传统的量子状态来自于物质界面的独特电子结构.
- 已知氧化物之间的接口可以容纳新出现的电子现象,包括超导.
研究的目的:
- 研究电子气体在涉及 (111) 导向的KTaO3的接口中的超导性.
- 将KTaO3接口的超导性能与已建立的系统 (如LaAlO3/SrTiO3) 进行比较.
主要方法:
- 在以111为导向的KTaO3和绝缘覆盖层 (EuO或LaAlO3) 之间制造接口.
- 电传输测量,包括关键场和电流电压特征.
- 温度依赖的电阻测量以确定超导过渡温度.
主要成果:
- 在EuO/KTaO3 (111) 和LaAlO3/KTaO3 (111) 界面发现了电子气体的超导性.
- 观察到超导过渡温度高达2.2凯尔文,比LaAlO3/SrTiO3高出一个数量级.
- 超导的二维性质得到了证实. 在超导之前,在EuO/KTaO3 (111) 样本中出现了明显的条形阶段.
结论:
- 面向111的KTaO3接口为新兴的超导提供了一个新平台.
- 与其他氧化物接口相比,观察到的超导性显著增强.
- 条纹相的出现表明这些接口上的电子相之间存在复杂的相互作用.
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