Spin liquid polymorphism in a correlated electron system on the threshold of superconductivity

Abstract

We report neutron scattering measurements, which reveal spin-liquid polymorphism in a '11' iron chalcogenide superconductor, a poorly-metallic magnetic FeTe tuned towards superconductivity by substitution of a small amount of Tellurium with iso-electronic Sulphur. We observe liquid-like magnetic dynamics, which is described by a competition of two phases with different local structure, whose relative abundance depends on temperature. One is the ferromagnetic (FM) plaquette phase observed in the non-superconducting FeTe, which preserves the C${}_4$ symmetry of the underlying square lattice and is favored at high temperatures. The other is the antiferromagnetic plaquette phase with broken C${}_4$ symmetry, which emerges with doping and is predominant at low temperatures. These findings suggest a first-order liquid-liquid phase transition in the electronic spin system of FeTe${}_{1-x}$(S,Se)${}_x$. We thus discover remarkable new physics of competing spin liquid polymorphs in a correlated electron system approaching superconductivity. Our results facilitate an understanding of large swaths of recent experimental data in unconventional superconductors.

5 pages, 4 figures

References in corpus (4)

• An Intrinsic Bond-Centered Electronic Glass with Unidirectional Domains in Underdoped Cuprates
• From (pi, 0) magnetic order to superconductivity with (pi, pi) magnetic resonance in Fe1.02(Te1-xSex)
• Magnetic excitations of Fe_{1+y}Se_xTe_{1-x} in magnetic and superconductive phases
• Magnetic hour-glass dispersion and its relation to high-temperature superconductivity in iron-tuned Fe${}_{1+y}$Te${}_{0.7}$Se${}_{0.3}$

Cited by in corpus (27)

• Tomonaga-Luttinger Liquid Behavior and Spinon Confinement in YbAlO${}_3$
• Magnetic, superconducting, and topological surface states on Fe${}_{1+y}$Te${}_{1-x}$Se${}_x$
• Magnetic ground state of the Ising-like antiferromagnet DyScO${}_3$
• Itinerancy enhanced quantum fluctuation of magnetic moments in iron-based superconductors
• Room temperature local nematicity in FeSe superconductor
• Antiferromagnetic ordering and dipolar interactions of YbAlO${}_3$
• The Magnetic Structure of Paramagnetic MnO
• Polarized neutron scattering on HYSPEC: the HYbrid SPECtrometer at SNS
• Double stage nematic bond-ordering above double stripe magnetism: application to BaTi${}_2$Sb${}_2$O
• Bicollinear Antiferromagnetic Order, Monoclinic Distortion, and Reversed Resistivity Anisotropy in FeTe as a Result of Spin-Lattice Coupling
• Photoinduced ultrafast dynamics of local nematicity and lattice distortions in FeSe crystals
• Signatures of coupling between spin waves and Dirac fermions in YbMnBi${}_2$
• Magnetism and superconductivity in Fe${}_{1+y}$Te${}_{1-x}$Se${}_x$
• The dual nature of magnetism in a uranium heavy fermion system
• Thermal evolution of antiferromagnetic correlations and tetrahedral bond angles in superconducting FeTe${}_{1-x}$Se${}_x$
• Magnetic molecular orbitals in MnSi
• Coexistence of superconductivity and short-range double-stripe spin correlations in Te-vapor annealed FeTe${}_{1-x}$Se${}_x$ with $x\le 0.2$
• Plaquette instability competing with bicollinear ground state in detwinned FeTe
• Possible Bicollinear Nematic State with Monoclinic Lattice Distortions in Iron Telluride Compounds
• "Forbidden" phonon: dynamical signature of bond symmetry breaking in the iron chalcogenides
• Nematic Fluctuations in an Orbital Selective Superconductor Fe${}_{1+y}$Te${}_{1-x}$Se${}_x$
• Spin dynamics and exchange interaction in orthoferrite TbFeO${}_3$ with non-Kramers rare-earth ion
• Quasi One-Dimensional Ising-like Antiferromagnetism in the Rare-earth Perovskite Oxide TbScO${}_3$
• Spin-isotropic continuum of spin excitations in antiferromagnetically ordered Fe${}_{1.07}$Te
• Unexpected Enhancement of Three-Dimensional Low-Energy Spin Correlations in Quasi-Two-Dimensional Fe${}_{1+y}$Te${}_{1-x}$Se${}_x$ System at High Temperature
• In-situ electrical and thermal transport properties of FeySe1-xTex films with ionic liquid gating
• Longitudinal modes of spin fluctuations in iron-based superconductors