We investigate the resistive anisotropy in CsV3Sb5 thin films within the charge density wave phase. Using a device structure with twelve electrodes symmetrically distributed in a circular shape, we measure the resistivity anisotropy by varying the current direction. A twofold resistivity anisotropy modulated by temperature is found, which is fully consistent with the electronic nematicity in CsV3Sb5, that is, the spontaneous rotational symmetry breaking by electronic degree of freedom. Additionally, the resistivity anisotropy also shows modest changes by applying magnetic fields, implying the possible chiral charge orders with time-reversal symmetry breaking. These findings provide deep insights into the correlated electronic states in Kagome materials and highlight the unique properties of CsV3Sb5 in the two-dimensional regime.
Soft Phonon Charge-Density Wave Formation in the Kagome Metal KV$_3$Sb$_5$
Zhejiang University（浙江大学）；Hangzhou Normal University（杭州师范大学）；University of Science and Technology of China（中国科学技术大学）；Zhejiang University of Technology（浙江工业大学）；Hefei National Research Center for Physical Sciences at the Microscale, University of Science and Technology of China（中国科学院微观尺度物理科学合肥国家研究中心，中国科学技术大学）
Uniaxial stress enhanced anisotropic magnetoresistance and superconductivity in the kagome superconductor LaRu$_{3}$Si$_{2}$
PSI Center for Neutron and Muon Sciences CNM（瑞士保罗谢勒研究所中子与μ子科学中心）；Wuhan National High Magnetic Field Center and School of Physics, Huazhong University of Science and Technology（华中科技大学物理学院武汉国家高磁场科学中心）；Institute for Solid State Physics (ISSP), University of Tokyo（东京大学固体物理研究所）
A Strongly Anisotropic Superconducting Gap in the Kagome Superconductor CsV$_3$Sb$_5$: A Study of Directional Point-Contact Andreev Reflection Spectroscopy
We have investigated the temperature dependence of the resistive upper critical fields ($μ_{0}H_{\rm c2}(T)$) for an Fe$_{1.05}$Te$_{0.85}$Se$_{0.15}$ single crystal, which exhibit superconductivity at $T_{\rm c} \sim 14 K, in magnetic fields of up to 55 T. Two-dimensional feature and superconducting fluctuations of the samples are found to be weak, because the resistive broadening effect on applied magnetic fields of up to 14 T is small. The Pauli paramagnetic effect is obviously evidenced by the strong suppression of the $μ_{0}H_{\rm c2}^{ab}(T)$ ($H \parallel ab$) curve and nearly isotropic…
Nonreciprocal charge transport phenomena are widely studied in two-dimensional superconductors, which demonstrate unidirectional-anisotropy magnetoresistances as a result of symmetry breaking. Here, we report a strong nonreciprocal transport phenomenon in superconducting CsV$_{3}$Sb$_{5}$ thin flakes. The second harmonic voltages, mainly originating from the rectification effect of vortex motion, are unambiguously developed with in-plane and out-of-plane magnetic fields, and their magnitudes are comparable to those in noncentrosymmetric superconductors. The second harmonic magnetoresistances s…
