Twofold symmetry of $c$-axis resistivity in topological kagome superconductor CsV$_3$Sb$_5$ with in-plane rotating magnetic field

TL;DR

This study reveals a twofold symmetry in the $c$-axis resistivity of CsV$_3$Sb$_5$, indicating nematic electronic states and anisotropic superconductivity with orthogonal orders, advancing understanding of its complex physical properties.

Contribution

It uncovers the orthogonal relationship between nematic electronic states and superconductivity in CsV$_3$Sb$_5$ through in-plane magnetic field rotation measurements.

Findings

Twofold symmetry of superconductivity observed

Unique in-plane nematic electronic state identified

Orthogonal relationship between nematicity and superconductivity

Abstract

In transition metal compounds, due to the interplay of charge, spin, lattice and orbital degrees of freedom, many intertwined orders exist with close energies. One of the commonly observed states is the so-called nematic electron state, which breaks the in-plane rotational symmetry. This nematic state appears in cuprates, iron-based superconductor, etc. Nematicity may coexist, affect, cooperate or compete with other orders. Here we show the anisotropic in-plane electronic state and superconductivity in a recently discovered kagome metal CsV$_3$Sb$_5$ by measuring $c$-axis resistivity with the in-plane rotation of magnetic field. We observe a twofold symmetry of superconductivity in the superconducting state and a unique in-plane nematic electronic state in normal state when rotating the in-plane magnetic field. Interestingly these two orders are orthogonal to each other in terms of the field direction of the minimum resistivity. Our results shed new light in understanding non-trivial physical properties of CsV$_3$Sb$_5$.