Pure nematic quantum critical point accompanied by a superconducting dome

Abstract

When a symmetry-breaking phase of matter is suppressed to a quantum critical point (QCP) at absolute zero, quantum-mechanical fluctuations proliferate. Such fluctuations can lead to unconventional superconductivity, as evidenced by the superconducting domes often found near magnetic QCPs in correlated materials. However, it remains unclear whether this superconductivity mechanism holds for QCPs of the electronic nematic phase, characterized by rotational symmetry breaking. Here, we demonstrate from systematic elastoresistivity measurements that nonmagnetic FeSe${}_{1-x}$Te${}_x$ exhibits an electronic nematic QCP showing diverging nematic susceptibility. This finding establishes two nematic QCPs in FeSe-based superconductors with contrasting accompanying phase diagrams. In FeSe${}_{1-x}$Te${}_x$, a superconducting dome is centered at the QCP, whereas FeSe${}_{1-x}$S${}_x$ shows no QCP-associated enhancement of superconductivity. We find that this difference is related to the relative strength of nematic and spin fluctuations. Our results in FeSe${}_{1-x}$Te${}_x$ present the first case in support of the superconducting dome being associated with the pure nematic QCP.

Submitted version. 9 pages, 7 figures (including Supplementary Information)

References in corpus (12)

• Superconductivity close to magnetic instability in Fe(Se1-xTex)0.82
• Incommensurate magnetic order in the alpha-Fe(Te,Se) superconductor systems
• First-order magnetic and structural phase transitions in Fe${}_{1+y}$Se${}_x$Te${}_{1-x}$
• Bulk Superconductivity at 14 K in Single Crystals of Fe1+yTexSe1-x
• Quantum Criticality
• 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
• Quasiparticle mass enhancement approaching optimal doping in a high-Tc superconductor
• Exotic Superconducting States in FeSe-based Materials
• Electronic in-plane symmetry breaking at field-tuned quantum criticality in CeRhIn5
• Suppression of electronic correlations by chemical pressure from FeSe to FeS
• Incoherent-coherent crossover and the pseudogap in Te-annealed superconducting Fe${}_{1+y}$Te${}_{1-x}$Se${}_x$ revealed by magnetotransport measurements

Cited by in corpus (5)

• Two superconducting states with broken time-reversal symmetry in FeSe1-xSx
• Spontaneous orbital polarization in the nematic phase of FeSe
• Resurgence of superconductivity and the role of $d_{xy}$ hole band in FeSe${}_{1-x}$Te${}_x$
• Charge Transport in Ba${}_{1-x}$Rb${}_x$Fe${}_2$As${}_2$ Single Crystals
• Uniaxial stress effect on the electronic structure of quantum materials