P Sajilesh K, Kushwaha Roshan Kumar, Samanta Dibyendu, Tula Tymoteusz, Meena Pavan Kumar, Srivastava Shashank, Singh Deepak, Biswas Pabitra Kumar, Kanigel Amit, Hillier Adrian D, Ghosh Sudeep Kumar, Singh Ravi Prakash
Department of Physics, Indian Institute of Science Education and Research Bhopal, Bhopal, Madhya Pradesh, 462066, India.
Physics Department, Technion-Israel Institute of Technology, Haifa, 32000, Israel.
Adv Mater. 2025 Feb;37(7):e2415721. doi: 10.1002/adma.202415721. Epub 2024 Dec 26.
Weyl semimetals are a novel class of topological materials with unique electronic structures and distinct properties. HfRhGe stands out as a noncentrosymmetric Weyl semimetal with unconventional superconducting characteristics. Using muon-spin rotation and relaxation (µSR) spectroscopy and thermodynamic measurements, a fully gapped superconducting state is identified in HfRhGe that breaks time-reversal symmetry at the superconducting transition. This breaking can trigger a topological phase transition, as time-reversal symmetry protects the normal-state Weyl topology characterized by comprehensive first-principles calculations. Ginzburg-Landau analysis suggests an unconventional loop supercurrent superconducting state realized in HfRhGe. The presence of multiple Weyl points near the Fermi level and surface Fermi arcs dispersing across the Fermi level further support HfRhGe as a promising platform for topological superconductivity. Additionally, its noncentrosymmetric nature with time-reversal symmetry breaking superconducting state suggests that it can exhibit an intrinsic superconducting diode effect, offering novel optical and transport properties, with potential applications in dissipationless quantum electronics.
外尔半金属是一类具有独特电子结构和鲜明特性的新型拓扑材料。铪铑锗作为一种具有非常规超导特性的非中心对称外尔半金属脱颖而出。通过μ子自旋旋转与弛豫（µSR）光谱学和热力学测量，在铪铑锗中识别出一种完全能隙超导态，该超导态在超导转变时打破了时间反演对称性。这种打破会引发拓扑相变，因为时间反演对称性保护了由全面的第一性原理计算所表征的正常态外尔拓扑结构。金兹堡 - 朗道分析表明铪铑锗中实现了一种非常规的环形超流超导态。费米能级附近多个外尔点的存在以及跨越费米能级的表面费米弧进一步支持铪铑锗作为拓扑超导的一个有前景的平台。此外，其具有打破时间反演对称性超导态的非中心对称性质表明它可以展现出本征超导二极管效应，提供新颖的光学和输运特性，在无耗散量子电子学中具有潜在应用。
