Fragile pressure-induced magnetism in FeSe superconductors with a thickness reduction

Abstract

The emergence of high transition temperature ($T_c$) superconductivity in bulk FeSe under pressure is associated with the tuning of nematicity and magnetism. However, sorting out the relative contributions from magnetic and nematic fluctuations to the enhancement of $T_c$ remains challenging. Here, we design and conduct a series of high-pressure experiments on FeSe thin flakes. We find that, as the thickness decreases, the nematic phase boundary on temperature-pressure phase diagrams remains robust while the magnetic order is significantly weakened. A local maximum of $T_c$ is observed outside the nematic phase region, not far from the extrapolated nematic endpoint in all samples. However, the maximum $T_c$ value is reduced associated with the weakening of magnetism. No high-$T_c$ phase is observed in the thinnest sample. Our results strongly suggest that nematic fluctuations alone can only have a limited effect while magnetic fluctuations are pivotal on the enhancement of $T_c$ in FeSe.

8 pages, 5 figures. This is the first draft of an accepted paper by Nano Letters

References in corpus (28)

• Quantum Criticality in Heavy Fermion Metals
• Superconductivity in single-layer films of FeSe with a transition temperature above 100 K
• Evidence for an electron nematic phase transition in underdoped iron pnictide superconductors
• Heavy Fermions and Quantum Phase Transitions
• The Structural Phase Transition in FeSe (Fe1+dSe)
• Nematic and meta-nematic transitions in the iron pnictides
• Why Does Undoped FeSe Become A High Tc Superconductor Under Pressure?
• Orbital-driven nematicity in FeSe
• Crystal structure of the new FeSe1-x superconductor
• Enhancement of superconductivity near a nematic quantum critical point
• Origin of the tetragonal-to-orthorhombic (nematic) phase transition in FeSe: a combined thermodynamic and NMR study
• Thermodynamic evidence for nematic phase transition at the onset of pseudogap in YBa${}_2$Cu${}_3$O${}_y$
• Nematicity, magnetism and superconductivity in FeSe
• On the Remarkable Superconductivity of FeSe and its Close Cousins
• Tuning phase transitions of FeSe thin flakes by field effect transistor with solid ion conductor as gate dielectric
• Preformed Cooper pairs in layered FeSe-based superconductors
• Pressure-induced high-temperature superconductivity retained at ambient
• Suppression of superconductivity and enhanced critical field anisotropy in thin flakes of FeSe
• Dumbbell Defects in FeSe Films: A Scanning Tunneling Microscopy and First-Principles Investigation
• Interplay of nematic and magnetic orders in FeSe under pressure
• Non-Fermi liquid transport in the vicinity of nematic quantum critical point of FeSe${}_{1-x}$S${}_x$ superconductor
• Evolution of the Phase Diagram of LaFeP${}_{1-x}$As${}_x$O${}_{1-y}$F${}_y$ ($y$ = 0 -- 0.1)
• Evidence for d-wave superconductivity in single layer FeSe/SrTiO3 probed by quasiparticle scattering off step edges
• Evolution of transport properties in FeSe thin flakes with thickness approaching the two-dimensional limit
• Impact of Nematicity on the Relationship between Antiferromagnetic Fluctuations and Superconductivity in FeSe0.91S0.09 Under Pressure
• Lattice-Shifted Nematic Quantum Critical Point in FeSe${}_{1-x}$S${}_x$
• Importance of dxy orbital and electron correlation in iron-based superconductors revealed by phase diagram for 1111-system
• Tomonaga Luttinger liquid in the topological edge channel of multilayer FeSe

Cited by in corpus (4)

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• Anomalous Hall effect and two-dimensional Fermi surfaces in the charge-density-wave state of kagome metal RbV${}_3$Sb${}_5$
• Probing the Evolution of Electron Spin Wavefunction of NV Center in diamond via Pressure Tuning
• Robust superconductivity and fragile magnetism induced by the strong Cu impurity scattering in the high-pressure phase of FeSe