Twofold symmetry of c-axis resistivity in topological kagome superconductor CsV3Sb5 with in-plane rotating magnetic field

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 CsV3Sb5 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 CsV3Sb5.

Tunable nodal kagome superconductivity in charge ordered RbV3Sb5

“…As long as the charge ordered state preserves the point-group symmetry of the disordered state, the chiral pairing symmetry is expected to be retained below T co , suggesting a nodeless superconducting state. However, if the chargeordered state breaks the threefold rotational symmetry of the lattice, as proposed experimentally [53] and theoretically [18,21] for certain AV 3 Sb 5 compounds, a nodal gap is stabilized for a sufficiently large charge order parameter, as we show in the supplementary material. In this case, the nodal-to-nodeless transition does not coincide with the full suppression of charge order, unless the transition from the charge-ordered superconducting state to the "pure" superconducting state is first-order.…”

Microscopic structure of three-dimensional charge order in kagome superconductor AV3Sb5 and its tunability

“…Nevertheless, the X-ray structural refinements on CsV3Sb5 revealed the modulation pattern containing an alternating TrH and SoD structure without staggering 31 , in close analogy with the LLL structure obtained here. We note that in CsV3Sb5, signatures of bulk rotational symmetry breaking and surface stripe order emerge only below the characteristic temperature TSO » 60 K and not in the pure charge-ordered state between TCO » 94 K and TSO » 60 K 7,10 . This suggests that the 3D-CO itself does not break C6 rotational symmetry, which is indeed the case for the LLL structure revealed in the present study (Fig.…”

“…In close analogy with other strongly correlated systems such as Cu- 3 and Fe-based high-temperature superconductors 4 , as well as twisted Moiré superlattices 5 , a cascade of coupled symmetry-broken electronic orders has been observed in AV3Sb5. These include translational symmetry breaking in the form of 2´2 charge order (CO) below TCO » 78~102 K 2,6 , rotational symmetry breaking in the form of unidirectional 1´4 stripe order below TSO » 50~60 K [7][8][9][10] , a time-reversal symmetry breaking orbital flux phase below Tf » 70 K 11 , and superconductivity below Tc » 0.92~2.5 K 2,12,13 .…”

“…As an example, if CO crystallizes in the inverse MLL, MLL, or MML phases (Fig. 1k-m), C6-rotational symmetry is spontaneously broken, which may provide a natural explanation for the unidirectional 1´4 stripe order and electronic nematicity emerging below TCO [7][8][9][10] . However, the detailed microscopic structure of 3D-CO and its composition dependence in AV3Sb5 series have not been conclusively reported so far, with different approaches -X-ray diffraction 31,32 , coherent phonon spectroscopy 33 , nuclear magnetic/quadrupole resonance 34 , scanning tunneling microscopy 27 , and DFT 35 -yielding divergent results.…”

Coexistence of Multiple Stacking Charge Density Waves in Kagome Superconductor ${\mathrm{CsV}}_3{\mathrm{Sb}}_5$

“…ture of 4c on cooling (∼ 89 K) is found to be lower than the corresponding disappearance temperature on warming (∼ 92.8 K). An intriguing quenched state due to fast cooling is observed in warming experiment, which could have critical implications in interpreting experimental anomalies at about 60 ∼ 70 K [38][39][40][41]. Comparison with computed diffraction patterns based on DFT calculations suggests the observed CDW structures arise from different stackings of ISD deformed V-containing layers.…”