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

AbstractIn 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.

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ELEMENTARY EXCITATIONS DUE TO ORBITAL DEGREES OF FREEDOM IN IRON-BASED SUPERCONDUCTORS

International Journal of Modern Physics B ◽

10.1142/s0217979213300144 ◽

2013 ◽

Vol 27 (20) ◽

pp. 1330014 ◽

Cited By ~ 10

Author(s):

WEI-CHENG LEE ◽

WEICHENG LV ◽

HAMOOD Z. ARHAM

Keyword(s):

Phase Transition ◽

Structural Phase Transition ◽

Degrees Of Freedom ◽

Rotational Symmetry ◽

Structural Phase ◽

Iron Based Superconductors ◽

Elementary Excitations ◽

Lattice Symmetry ◽

Iron Based ◽

Intense Debate

One central issue under intense debate in the study of the iron-based superconductors is the origin of the structural phase transition that changes the crystal lattice symmetry from tetragonal to orthorhombic. This structural phase transition, occurring universally in almost every family of the iron-based superconductors, breaks the lattice C4 rotational symmetry and results in an anisotropy in a number of physical properties. Due to the unique topology of the Fermi surface, both orbital- and spin-based scenarios have been proposed as the driving force. In this review, we focus on theories from the orbital-based scenario and discuss several related experiments. It is pointed out that although both scenarios lead to the same macroscopic phases and are not distinguishable in bulk measurements of the thermodynamic properties, the elementary excitations could be fundamentally different, and provide us with the possibility to resolve this long-standing debate between orbital- and spin-based theories.

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Novel electronic nematicity in heavily hole-doped iron pnictide superconductors

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1909172117 ◽

2020 ◽

Vol 117 (12) ◽

pp. 6424-6429 ◽

Cited By ~ 4

Author(s):

Kousuke Ishida ◽

Masaya Tsujii ◽

Suguru Hosoi ◽

Yuta Mizukami ◽

Shigeyuki Ishida ◽

...

Keyword(s):

Liquid Crystalline ◽

Rotational Symmetry ◽

Quantum Liquid ◽

Iron Based Superconductors ◽

Iron Pnictide ◽

Tetragonal Lattice ◽

Nematic State ◽

Nematic Director ◽

Iron Based ◽

Electronic Nematicity

Electronic nematicity, a correlated state that spontaneously breaks rotational symmetry, is observed in several layered quantum materials. In contrast to their liquid-crystal counterparts, the nematic director cannot usually point in an arbitrary direction (XY nematics), but is locked by the crystal to discrete directions (Ising nematics), resulting in strongly anisotropic fluctuations above the transition. Here, we report on the observation of nearly isotropic XY-nematic fluctuations, via elastoresistance measurements, in hole-doped Ba1−xRbxFe2As2iron-based superconductors. While forx=0, the nematic director points along the in-plane diagonals of the tetragonal lattice, forx=1, it points along the horizontal and vertical axes. Remarkably, for intermediate doping, the susceptibilities of these two symmetry-irreducible nematic channels display comparable Curie–Weiss behavior, thus revealing a nearly XY-nematic state. This opens a route to assess this elusive electronic quantum liquid-crystalline state.

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