Multiple Superconducting Phases and Unusual Enhancement of the Upper Critical Field in UTe2

Abstract

We performed AC calorimetry and magnetoresistance measurements under pressure for H || a-axis (easy-magnetization axis) in the novel heavy-fermion superconductor UTe2. Thanks to the thermodynamic information, multiple superconducting phases have been revealed under pressure and magnetic field. The (H,T) phase diagram of superconductivity under pressure displays an abrupt increase of the upper critical field (Hc2) at low temperature and in the high field region, and a strong convex curvature of Hc2 at high temperature. This behavior of Hc2 and the multiple superconducting phases require a state for the superconducting order parameter more complex than a spin-triplet equal spin pairing. Above the superconducting critical pressure, Pc, we find strong indications that the possible magnetic order is closer to antiferromagnetism than to ferromagnetism.

6 pages, 5 figures, accepted for publication in J. Phys. Soc. Jpn

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Cited by in corpus (74)

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• Field-induced tuning of the pairing state in a superconductor
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• Chiral superconductivity in UTe2 probed by anisotropic low-energy excitations
• Spatially inhomogeneous superconductivity in UTe2
• Topological crystalline superconductivity in locally noncentrosymmetric CeRh${}_2$As${}_2$
• Single-Component Superconductivity in UTe${}_2$ at Ambient Pressure
• A review of UTe${}_2$ at high magnetic fields
• Magnetic Properties under Pressure in Novel Spin-Triplet Superconductor UTe2
• Anapole superconductivity from $\mathcal{P}\mathcal{T}$-symmetric mixed-parity interband pairing
• Field-Induced Superconductivity near the Superconducting Critical Pressure in UTe2
• Field Induced Multiple Superconducting Phases in UTe2 along Hard Magnetic Axis
• Nonreciprocal optical response in parity-breaking superconductors
• Inhomogeneous Superconducting State Probed by ${}^{125}$Te NMR on UTe$_2
• Slow Electronic Dynamics in the Paramagnetic State of UTe${}_2$
• Discovery of magnetic phase transitions in heavy-fermion superconductor CeRh${}_2$As${}_2$
• Decoupling multi-phase superconductivity from normal state ordering in CeRh${}_2$As${}_2$
• Anisotropic magnetotransport properties of the heavy-fermion superconductor CeRh${}_2$As${}_2$
• Quantum-geometry-induced anapole superconductivity
• Enhancement and Discontinuity of Effective Mass through the First-Order Metamagnetic Transition in UTe${}_2$
• Feedback of superconductivity on the magnetic excitation spectrum of UTe${}_2$
• Expansion of the high field-boosted superconductivity in UTe2 under pressure
• Field-induced compensation of magnetic exchange as the possible origin of reentrant superconductivity in UTe${}_2$
• Thermodynamic signatures of short-range magnetic correlations in UTe${}_2$
• Longitudinal spin fluctuations driving field-reinforced superconductivity in UTe${}_2$
• Magnetic reshuffling and feedback on superconductivity in UTe2 under pressure
• Thermodynamic and electrical transport properties of UTe${}_2$ under uniaxial stress
• Pressure-induced structural phase transition and new superconducting phase in UTe2
• Electronic multipoles and multiplet pairs induced from Pomeranchuk and Cooper instabilities of Bogoliubov Fermi surfaces
• Molten Salt Flux Liquid Transport Method for Ultra Clean Single Crystals UTe2
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• Magnetovolume Effect on the First-Order Metamagnetic Transition in UTe${}_2$
• Piezoelectric effect and diode effect in anapole and monopole superconductors
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• Anisotropic signatures of the electronic correlations in the electrical resistivity of UTe${}_2$
• Multiple superconducting phases in heavy-fermion metals
• Superconducting piezoelectric effect
• Metastable phase of UTe${}_2$ formed under high pressure above 5 GPa
• Notes on multiple superconducting phases in UTe${}_2$ ---Third transition---
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• A quantum critical line bounds the high field metamagnetic transition surface in UTe${}_2$
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• Incommensurate antiferromagnetism in UTe2 under pressure
• Quasi-uniaxial pressure induced superconductivity in stoichiometric compound UTe${}_2$
• Effects of nucleation at a first-order transition between two superconducting phases: Application to CeRh${}_2$As${}_2$
• Reinforcement of superconductivity by quantum critical fluctuations of metamagnetism in UTe${}_2$
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• Violation of the orbital depairing limit in a non-unitary state --on the high field phase in the heavy Fermion superconductor UTe${}_2$--
• Anisotropic paramagnetic response of topological Majorana surface states in the superconductor ${\text{UTe}}_2$
• Theoretical studies on off-axis phase diagrams and Knight shifts in UTe${}_2$ -- Tetra-critical point, d-vector rotation, and multiple phases
• The phase diagram of CeRh${}_2$As${}_2$ for out-of-plane magnetic field
• Intrinsic low-temperature magnetic properties on the ultra-clean UTe${}_2$ with $T_{\mathrm{c}}$ = 2.1 K revealed by ${}^{125}$Te NMR
• Competition of vortex core structures in superfluid ${}^3$He-B
• Pair-Kondo effect: a mechanism for time-reversal broken superconductivity in UTe${}_2$
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• Self-reconstruction of order parameter in spin-triplet superconductor UTe${}_2$
• Reciprocal and nonreciprocal paraconductivity in bilayer multiphase superconductors
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• Metamagnetism in the high-pressure tetragonal phase of UTe${}_2$
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• Pressure-enhanced $f$-electron orbital weighting in UTe2 mapped by quantum interferometry