Evidence for a pressure-induced antiferromagnetic quantum critical point in intermediate valence UTe2

Abstract

UTe${}_2$ is a recently discovered unconventional superconductor that has attracted much interest due to its many intriguing properties - a large residual density-of-states in the superconducting state, re-entrant superconductivity in high magnetic fields, and potentially spin-triplet topological superconductivity. Our ac calorimetry, electrical resistivity, and x-ray absorption study of UTe${}_2$ under applied pressure reveals key new insights on the superconducting and magnetic states surrounding pressure-induced quantum criticality at P${}_{c1}$ = 1.3 GPa. First, our specific heat data at low pressures, combined with a phenomenological model, show that pressure alters the balance between two closely competing superconducting orders. Second, near 1.5 GPa we detect two bulk transitions that trigger changes in the resistivity which are consistent with antiferromagnetic order, rather than ferromagnetism. The presence of both bulk magnetism and superconductivity at pressures above P${}_{c2}$ = 1.4 GPa results in a significant temperature difference between resistively and thermodynamically determined transitions into the superconducting state, which indicates a suppression of the superconducting volume fraction by magnetic order. Third, the emergence of magnetism is accompanied by an increase in valence towards a U${}^{4+}$ (5f2) state, which indicates that UTe${}_2$ exhibits intermediate valence at ambient pressure. Our results suggest that antiferromagnetic fluctuations may play a more significant role on the superconducting state of UTe${}_2$ than previously thought.

arXiv comment21 pages, 7 figures; added section S1 to supplemental, fixed geometrical factors in current density measurements

References in corpus (20)

• Topological superconductors: a review
• Spontaneously polarized half-gapped superconductivity
• Hidden Magnetism and Quantum Criticality in the Heavy Fermion Superconductor CeRhIn5
• Microscopic evidence for a chiral superconducting order parameter in the heavy fermion superconductor UTe2
• Unconventional Superconductivity in Heavy Fermion UTe2
• Extreme magnetic field-boosted superconductivity
• Review of U-based Ferromagnetic Superconductors: Comparison between UGe2, URhGe, and UCoGe
• Complete pressure dependent phase diagrams for SrFe2As2 and BaFe2As2
• Multiple superconducting phases in a nearly ferromagnetic system
• Coexistence of ferromagnetic fluctuations and superconductivity in the actinide superconductor UTe2
• Multiple Superconducting Phases and Unusual Enhancement of the Upper Critical Field in UTe2
• Superconducting Properties of Heavy Fermion UTe${}_2$ Revealed by ${}^{125}$Te-Nuclear Magnetic Resonance
• Quasi-two-dimensional Fermi surfaces and unitary spin-triplet pairing in the heavy fermion superconductor UTe${}_2$
• Enhanced spin triplet superconductivity due to Kondo destabilization
• Anisotropy of the Upper Critical Field in the Heavy-Fermion Superconductor UTe2 under Pressure
• Tuning magnetic confinement of spin-triplet superconductivity
• Probing 5f-state configurations in URu2Si2 with U L3-edge resonant x-ray emission spectroscopy
• Anomalous Anisotropy of the Lower Critical Field and Meissner Effect in UTe2
• Weyl Superconductivity in UTe2
• Specific heat at the transition in a superconductor with fluctuating magnetic moments

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• Topological band and superconductivity in UTe${}_2$
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• Anisotropic response of spin susceptibility in the superconducting state of UTe${}_2$ probed with ${}^{125}$Te-NMR measurement
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• Field-Induced Superconductivity near the Superconducting Critical Pressure in UTe2
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• Field Induced Multiple Superconducting Phases in UTe2 along Hard Magnetic Axis
• Inhomogeneous Superconducting State Probed by ${}^{125}$Te NMR on UTe$_2
• Enhanced triplet superconductivity in next generation ultraclean UTe2
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