Evidence chain for time-reversal symmetry-breaking kagome superconductivity

Abstract

Superconductivity and magnetism are antagonistic quantum matter, while their intertwining has long been considered in frustrated-lattice systems1-3. In this work, we utilize scanning tunneling microscopy and muon spin resonance to discover time-reversal symmetry-breaking superconductivity in kagome metal Cs(V,Ta)3Sb5, where the Cooper pairing exhibits magnetism and is modulated by it. In the magnetic channel, we observe spontaneous internal magnetism in a full-gap superconducting state. Under perturbations of inverse magnetic fields, we detect a time-reversal asymmetrical interference of Bogoliubov quasi-particles at a circular vector. At this vector, the pairing gap spontaneously modulates, which is distinct from pair density waves occurring at a point vector and consistent with the theoretical proposal of unusual interference effect under time-reversal symmetry-breaking. The correlation between internal magnetism, Bogoliubov quasi-particles, and pairing modulation provides a chain of experimental clues for time-reversal symmetry-breaking kagome superconductivity.

To appear in Nature Materials (2024)

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Cited by in corpus (20)

• Signatures of Chiral Superconductivity in Rhombohedral Graphene
• Kagome metals
• Search for orbital magnetism in the kagome superconductor $\mathrm{Cs}{\mathrm{V}}_3\mathrm{S}{\mathrm{b}}_5$ using neutron diffraction
• AV${}_3$Sb${}_5$ kagome superconductors: a review with transport measurements
• Perspective: imaging atomic step geometry to determine surface terminations of kagome materials and beyond
• Pair-breaking scattering interference as a mechanism for superconducting gap modulation
• Thermomodulated intrinsic Josephson effect in Kagome CsV3Sb5
• Imaging half-unit-cell Cooper-pair density waves in monolayer 1T${}^{\prime }$-MoTe${}_2$
• Common sublattice-pure van Hove singularities in the kagome superconductors $\text{A}$V${}_3$Sb${}_5$ ($\text{A}$ = K, Rb, Cs)
• Switchable chiral 2x2 pair density wave in pure CsV3Sb5
• Unveiling the nature of electronic transitions in RbV${}_3$Sb${}_5$ with Avoided Level Crossing $\mu$SR
• Phase-sensitive evidence for pair density waves in a kagome superconductor
• Recent progress in quantum spin liquids, fractional magnetization plateaus, and unconventional superconductivity in kagome lattices
• Many-body electronic structure in pyrochlore superconductor CsBi2 and spin liquid Pr2Ir2O7
• The possible frustrated superconductivity in the kagome superconductors
• Orbital current signature using neutron diffraction
• Topological in-gap chiral edge states in superconducting Haldane model with spin-orbit coupling
• Beyond kagome: $p$-bands in kagome metals
• Topological pair density waves in kagome superconductors
• Josephson spectroscopy study of kagome superconductors toward the deep point-contact regime