Nontrivial Fermi surface topology of the kagome superconductor CsV3Sb5 probed by de Haas–van Alphen oscillations
Nontrivial Fermi surface topology of the kagome superconductor CsV3Sb5 probed by de Haas–van Alphen oscillations
复制标题
通过德哈斯范阿尔芬振荡探测 Kagome 超导体 CsV3Sb5 的非平凡费米表面拓扑
DOI：
10.1103/physrevb.105.024508
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发表时间：
2022
影响因子：
3.7
通讯作者：
Welp, U.
中科院分区：
文献类型：
--
作者：
Shrestha, K.;Chapai, R.;Pokharel, Bal K.;Miertschin, D.;Nguyen, T.;Zhou, X.;Chung, D. Y.;Kanatzidis, M. G.;Mitchell, J. F.;Welp, U.
我们使用扭矩磁力计研究了 Kagome 超导体的正常状态费米表面特性，施加的场 () 高达 35 T。扭矩信号显示出高于 15 T 的清晰的德哈斯-范阿尔芬 (dHvA) 振荡。振荡是平滑的，由值从 18 T 到 2135 T 的七个不同频率组成。通过使用隧道二极管振荡器技术进行额外测量，进一步证实了更高频率的存在。在场方向相对于 c 轴的不同倾斜角 () 处测量的所有频率都显示出相关性，这意味着与这些频率对应的费米面是二维 (2D) 的。 dHvA 振荡的缺失进一步支持了二维费米面的存在。根据朗道能级扇形图确定的所有频率的贝里相位 () 为 0.4。该值接近非平凡系统的理论值 = 0.5，这有力地支持了这些频率的费米面的非平凡拓扑。采用 Lifshitz-Kosevich 理论计算了表征费米表面的几个物理量。这些发现对于探索非平凡能带拓扑、电荷密度波和非常规超导之间的相互作用至关重要。
We have investigated the normal state Fermi-surface properties of the kagome superconductorusing torque magnetometry with applied fields () up to 35 T. The torque signal shows clear de Haas–van Alphen (dHvA) oscillations above 15 T. The oscillations are smooth and consist of seven distinct frequencies with values from18 T to 2135 T. The presence of higher frequencies inis further confirmed by carrying out additional measurements using the tunnel diode oscillator technique. All frequencies measured at different tilt angles () of the field direction with respect to the c axis show adependence, implying that the Fermi surfaces corresponding to these frequencies are two dimensional (2D). The absence of dHvA oscillations at=further supports the presence of 2D Fermi surfaces. The Berry phase () determined from the Landau level fan diagram for all frequencies is0.4. This value is close to the theoretical value of= 0.5 for a nontrivial system, which strongly supports the nontrivial topology of the Fermi surfaces of these frequencies. Several quantities characterizing the Fermi surface are calculated employing the Lifshitz-Kosevich theory. These findings are crucial for exploring the interplay between nontrivial band topology, charge-density wave, and unconventional superconductivity of.