近日，美国国家标准与技术研究院Peter Czajka团队研究了UTe2中的高场超导晕。2025年7月31日，《科学》杂志发表了这一成果。
重费米子材料UTe2是一种候选拓扑超导体，具有多个磁场诱导超导相。
其中一个这样的相只存在于大于40特斯拉的场中，这是一个相当大的尺度，因为它的临界温度只有2K。研究组将这种状态的测量扩展到bc晶体平面外的场，并揭示了它的核心结构：超导相以晕状的方式包裹在b轴周围，似乎被垂直于磁易轴的场分量稳定。这种角度依赖关系指向库珀对具有有限角动量的多分量自旋三重态序参数。配对机制仍然是谜，UTe2特定的亲磁超导倾向似乎与现有的场增强超导模型不相容。
附：英文原文
Title: High-field superconducting halo in UTe2
Author: Sylvia K. Lewin, Peter Czajka, Corey E. Frank, Gicela Saucedo Salas, G. Timothy Noe II, Hyeok Yoon, Yun Suk Eo, Johnpierre Paglione, Andriy H. Nevidomskyy, John Singleton, Nicholas P. Butch
Issue&Volume: 2025-07-31
Abstract: The heavy fermion material UTe2 is a candidate topological superconductor that exhibits multiple magnetic field–induced superconducting phases. One such phase exists only at fields greater than 40 tesla, a considerable scale given its critical temperature of only 2 K. Here, we extend measurements of this state with fields outside of the bc crystallographic plane and reveal its core structure: The superconducting phase wraps around the b axis in a halo-like fashion and appears to be stabilized by a field component perpendicular to the magnetic easy axis. This angle dependence points to a multicomponent spin-triplet order parameter with a finite angular momentum of the Cooper pairs. The pairing mechanism remains enigmatic, and UTe2’s specific magnetophilic superconducting tendencies seem incompatible with existing models for field-enhanced superconductivity.
DOI: adn7673
Source: https://www.science.org/doi/10.1126/science.adn7673