Evidence of a hidden flux phase in the topological kagome metal CsV${}_3$Sb${}_5$

Abstract

Phase transitions governed by spontaneous time reversal symmetry breaking (TRSB) have long been sought in many quantum systems, including materials with anomalous Hall effect (AHE), cuprate high temperature superconductors, Iridates and so on. However, experimentally identifying such a phase transition is extremely challenging because the transition is hidden from many experimental probes. Here, using zero-field muon spin relaxation (ZF-$\mu$SR) technique, we observe strong TRSB signals below 70 K in the newly discovered kagome superconductor CsV${}_3$Sb${}_5$. The TRSB state emerges from the 2 x 2 charge density wave (CDW) phase present below ~ 95 K. By carrying out optical second-harmonic generation (SHG) experiments, we also find that inversion symmetry is maintained in the temperature range of interest. Combining all the experimental results and symmetry constraints, we conclude that the interlayer coupled chiral flux phase (CFP) is the most promising candidate for the TRSB state among all theoretical proposals of orbital current orders. Thus, this prototypical kagome metal CsV3Sb5 can be a platform to establish a TRSB current-ordered state and explore its relationship with CDW, giant AHE, and superconductivity.

17 pages, 3 figures

References in corpus (14)

• Topological Mott Insulators
• Roton pair density wave and unconventional strong-coupling superconductivity in a topological kagome metal
• Charge density waves and electronic properties of superconducting kagome metals
• Magnetic order in the pseudogap phase of high-$T_C$ superconductors
• Concurrence of anomalous Hall effect and charge density wave in a superconducting topological kagome metal
• Electronic instabilities of kagome metals: saddle points and Landau theory
• Rotation symmetry breaking in the normal state of a kagome superconductor KV3Sb5
• Fermi surface mapping and the nature of charge density wave order in the kagome superconductor CsV${}_3$Sb${}_5$
• Complex charge density waves at Van Hove singularity on hexagonal lattices: Haldane-model phase diagram and potential realization in kagome metals ${\text{AV}}_3{\text{Sb}}_5$
• Theoretical prediction of a strongly correlated Dirac metal
• Doped Kagome System as Exotic Superconductor
• Coherent phonon spectroscopy and interlayer modulation of charge density wave order in the kagome metal CsV${}_3$Sb${}_5$
• Distinctive momentum dependent charge-density-wave gap observed in CsV${}_3$Sb${}_5$ superconductor with topological Kagome lattice
• Low-energy effective theory and symmetry classification of flux phases on Kagome lattice

Cited by in corpus (39)

• Kagome superconductors AV${}_3$Sb${}_5$ (A=K, Rb, Cs)
• Quantum states and intertwining phases in kagome materials
• AV${}_3$Sb${}_5$ Kagome Superconductors: Progress and Future Directions
• Chern Fermi pocket, topological pair density wave, and charge-4e and charge-6e superconductivity in kagome superconductors
• Charge order landscape and competition with superconductivity in kagome metals
• A unique van Hove singularity in kagome superconductor CsV${}_{3-x}$Ta${}_x$Sb${}_5$ with enhanced superconductivity
• No observation of chiral flux current in the topological kagome metal CsV${}_3$Sb${}_5$
• Observation of Flat Band, Dirac Nodal Lines and Topological Surface States in Kagome Superconductor CsTi${}_3$Bi${}_5$
• Anomalous thermoelectric effects and quantum oscillations in the kagome metal CsV${}_3$Sb${}_5$
• Correlated order at the tipping point in the kagome metal CsV${}_3$Sb${}_5$
• Tuning the van Hove singularities in AV${}_3$Sb${}_5$ (A = K, Rb, Cs) via pressure and doping
• Competing superconductivity and charge-density wave in Kagome metal CsV3Sb5: evidence from their evolutions with sample thickness
• Unidirectional coherent quasiparticles in the high-temperature rotational symmetry broken phase of AV3Sb5 kagome superconductors
• Charge-loop current order and Z3 nematicity mediated by bond-order fluctuations in kagome metal AV3Sb5 (A=Cs,Rb,K)
• Three-dimensional energy gap and origin of charge-density wave in kagome superconductor KV3Sb5
• Crucial role of out-of-plane Sb-$p$ orbitals in Van Hove singularity formation and electronic correlation for superconducting Kagome metal CsV${}_3$Sb${}_5$
• Screening promising CsV3Sb5-like kagome materials from systematic first-principles evaluation
• Dynamical Study of the Origin of the Charge Density Wave in $A$V${}_3$Sb${}_5$ ($A=$K, Rb, Cs) Compounds
• Magneto-Seebeck effect and ambipolar Nernst effect in CsV${}_3$Sb${}_5$ superconductor
• Perspective on the muon-spin rotation/relaxation under hydrostatic pressure
• Electronic properties of correlated kagomé metals AV${}_3$Sb${}_5$(A = K, Rb, Cs): A perspective
• Drastic magnetic-field-induced chiral current order and emergent current-bond-field interplay in kagome metals
• Altermagnetic Ground State in Distorted Kagome Metal CsCr${}_3$Sb${}_5$
• Superconductivity modulated by structural phase transitions in pressurized vanadium-based kagome metals
• Anomalous Hall effect and two-dimensional Fermi surfaces in the charge-density-wave state of kagome metal RbV${}_3$Sb${}_5$
• Higher-order Oscillatory Planar Hall Effect in Topological Kagome Metal
• Multiband effects in thermoelectric and electrical transport properties of kagome superconductors $A$V${}_3$Sb${}_5$ ($A$ = K, Rb, Cs)
• Topological superconductivity and large spin Hall effect in the kagome family Ti6X4 (X = Bi, Sb, Pb, Tl, In)
• Emergent topological quantum orbits in the charge density wave phase of kagome metal CsV${}_3$Sb${}_5$
• Large Fermi surface in pristine kagome metal CsV${}_3$Sb${}_5$ and enhanced quasiparticle effective masses
• Violation of Emergent Rotational Symmetry in the Hexagonal Kagome Superconductor CsV3Sb5
• Statistical learning of engineered topological phases in the kagome superlattice of AV${}_3$Sb${}_5$
• Impact of the orbital current order on the superconducting properties of the kagome superconductors
• Kagome materials $A$V${}_3$Sb${}_5$ ($A$=K,Rb,Cs): pairing symmetry and pressure-tuning studies
• Two-dimensional phase diagram of the charge density wave in doped CsV${}_3$Sb${}_5$
• Electrical and thermal transport properties of kagome metals AV${}_3$Sb${}_5$ (A=K, Rb, Cs)
• Magnetoresistance hysteresis in the superconduting state of Kagome CsV${}_3$Sb${}_5$
• Incommensurate charge-stripe correlations in the kagome superconductor CsV${}_3$Sb${}_{5-x}$Sn${}_x$
• New mechanisms to engineer magnetic skyrmions and topological superconductors