在UTe2中观察持久的零模式和超导双体
Nileema Sharma1,2, Matthew Toole1,2, James McKenzie1,2
1Department of Physics and Astronomy, University of Notre Dame, Notre Dame, Indiana 46556, United States.
ACS nano
|August 26, 2025
概括
研究人员使用扫描道显微镜可视化UTe2中的超导. 这揭示了时间逆转不变的超导和潜在的马约拉纳零模式.
科学领域:
- 凝聚物质物理学
- 超导性研究
- 材料科学
背景情况:
- 超导提供了电子配对和拓状态的见解.
- 在原子尺度上可视化大量自旋三极超导体的仍然具有挑战性.
- UTe2 是一个具有难以捉摸的顺序参数和不确定的时间逆向对称 (TRS) 状态的高级旋转三极超导体.
研究的目的:
- 在原子尺度上可视化UTe2中的超导.
- 研究UTe2中的超导性,特别是关于时间逆向对称性的研究.
- 在中探索拓状态的潜在存在,例如Majorana零模式.
主要方法:
- 使用扫描道显微镜 (STM) 在超纯的UTe2单晶 (Tc = 2.1 K) 上.
- 采用d2I/dV2成像,这是一个有效的技术,用于在具有显著的零能量密度 (DOS) 的超导体中进行形可视化.
- 应用了小型外平面磁场来诱导状格子的形成.
主要成果:
- 成功可视化了沿 a 轴 (12 nm) 和垂直于它 (4 nm) 的不同连贯长度的异构单流量子.
- 观察了三角格 (VL) 的形成,其结构和格子在磁场极性和冷却历史的变化下保持不变,支持时间逆转的不变超导.
- 检测到持续的,不分割的,光谱尖的零偏导峰 (ZBPs) 在高达8 T的旋核心,与对称性保护的Majorana零模式 (MZMs) 相一致.
- 在旋结构中发现了镜像不对称的双重组,其中一个组件呈现ZBP,另一个则呈现增强的明显间隙,这可能表明场诱导的多组件顺序参数.
结论:
- 这项研究提供了大量自旋三极超导体UTe2中的第一个原子尺度可视化.
- 实验证据强烈支持UTe2在零场下的时间逆转不变超导.
- 在芯中观察到的零偏导峰与Majorana零模式的存在一致,这表明UTe2具有拓超导性.
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