Strongly correlated superconductivity in a copper-based metal-organic framework with a perfect kagome lattice

Abstract

Metal-organic frameworks (MOFs), which are self-assemblies of metal ions and organic ligands, provide a tunable platform to search a new state of matter. A two-dimensional (2D) perfect kagome lattice, whose geometrical frustration is a key to realizing quantum spin liquids, has been formed in the $\pi$-$d$ conjugated 2D MOF [Cu${}_3$(C${}_6$S${}_6$)]${}_n$ (Cu-BHT). The recent discovery of its superconductivity with a critical temperature $T_{\mathrm{c}}$ of 0.25\,kelvin raises fundamental questions about the nature of electron pairing. Here, we show that Cu-BHT is a strongly correlated unconventional superconductor with extremely low superfluid density. A nonexponential temperature dependence of superfluid density is observed, indicating the possible presence of superconducting gap nodes. The magnitude of superfluid density is much smaller than those in conventional superconductors, and follows the Uemura's relation of strongly correlated superconductors. These results imply that the unconventional superconductivity in Cu-BHT originates from electron correlations related to spin fluctuations of kagome lattice.

arXiv comment4 figures

References in corpus (24)

• Magic-angle graphene superlattices: a new platform for unconventional superconductivity
• Quantum Spin Liquids
• Quantum Criticality in Heavy Fermion Metals
• Kramers-Kronig constrained variational analysis of optical spectra
• High Temperature Superconductivity in Iron Pnictides and Chalcogenides
• Magnetic Penetration Depth in Unconventional Superconductors
• A Sharp Peak of the Zero-Temperature Penetration Depth at Optimal Composition in BaFe2(As1-xPx)2
• Quantum frustration in organic Mott insulators: from spin liquids to unconventional superconductors
• Line nodes in the energy gap of high-temperature superconducting BaFe_2(As_{1-x}P_x)_2 from penetration depth and thermal conductivity measurements
• Meissner - London state in superconductors of rectangular cross-section in perpendicular magnetic field
• Beyond Triplet: Unconventional Superconductivity in a Spin-3/2 Topological Semimetal
• Evidence for nodal quasiparticles in electron-doped cuprates from penetration depth measurements
• Superconducting Two-Dimensional Metal-Organic Framework
• Quantum criticality in a metallic spin liquid
• Pauli-limiting effects in the upper critical fields of a clean LiFeAs single crystal
• Magnetic penetration depth of single crystal SmFeAsO_{1-x}F_y: a fully gapped superconducting state
• Condensation, excitation, pairing, and superfluid density in high-$T_c$ superconductors: magnetic resonance mode as a roton analogue and a possible spin-mediated pairing
• First-Principles Design of a Half-Filled Flat Band of the Kagome Lattice in Two-Dimensional Metal-Organic Frameworks
• Designing Kitaev spin liquids in metal-organic frameworks
• Tunable Bi-frustrated Electron Spin and Charge States in a Cu-Hexaaminobenzene Framework
• Crystalline Kitaev spin liquids
• Anomalous superfluid density in quantum critical superconductors
• Effect of magnetic criticality and Fermi-surface topology on the magnetic penetration depth
• Evolution of quasiparticle excitations with critical mass enhancement in superconducting AFe2As2 (A = K, Rb, and Cs)

Cited by in corpus (14)

• Bulk evidence of anisotropic $s$-wave pairing with no sign change in the kagome superconductor CsV${}_3$Sb${}_5$
• Local gate control of Mott metal-insulator transition in a 2D metal-organic framework
• Two-dimensional Kagome Materials: Theoretical Insights, Experimental Realizations, and Electronic Structures
• Universal Fermi velocity in highly compressed hydride superconductors
• Spin-$0$ Mott insulator to metal to spin-$1$ Mott insulator transition in the single-orbital Hubbard model on the decorated honeycomb lattice
• Fully-gapped superconductivity with rotational symmetry breaking in pressurized kagome metal CsV${}_3$Sb${}_5$
• Spin Excitations of High Spin Iron(II) in Metal-Organic Chains on Metal and Superconductor
• Engineering two-dimensional kagome topological insulator from porous graphene
• $C_3$ symmetry breaking metal-insulator transitions in a flat band in the half-filled Hubbard model on the decorated honeycomb lattice
• Designing Topological High-Order Van Hove Singularities: Twisted Bilayer Kagomé
• High-Temperature Superconductivity from Finite-Range Attractive Interaction
• Intrinsic coherence length anisotropy in nickelate, and some pnictide, and chalcogenide superconductors
• Collective Buckling in Metal-Organic Framework Materials
• Quantum buckling in metal-organic framework materials