Observation of the in-plane magnetic field-induced phase transitions in FeSe

Abstract

We investigate the thermodynamic properties of FeSe under the in-plane magnetic fields using torque magnetometry, specific heat, magnetocaloric measurements. Below the upper critical field Hc2, we observed the field-induced anomalies at H1 ~ 15 T and H2 ~ 22 T near H//ab and below a characteristic temperature T* ~ 2 K. The transition magnetic fields H1 and H2 exhibit negligible dependence on both temperature and field orientation. This contrasts with the strong temperature and angle dependence of Hc2, suggesting that these anomalies are attributed to the field-induced phase transitions, originating from the inherent spin-density-wave instability of quasiparticles near the superconducting gap minima or possible Flude-Ferrell-Larkin-Ovchinnikov state in the highly spin-polarized Fermi surfaces. Our observations imply that FeSe, an atypical multiband superconductor with extremely small Fermi energies, represents a unique model system for stabilizing unusual superconducting orders beyond the Pauli limit.

8 pages, 4 figures, submitted

References in corpus (15)

• Fulde-Ferrell-Larkin-Ovchinnikov State in Heavy Fermion Superconductors
• Orbital-driven nematicity in FeSe
• Field-induced superconducting phase of FeSe in the BCS-BEC cross-over
• Emergence of the nematic electronic state in FeSe
• Phase diagram of a two-component Fermi gas with resonant interactions
• Reconstruction of Band Structure Induced by Electronic Nematicity in an FeSe Superconductor
• Ultra-cold Polarized Fermi Gases
• The key ingredients of the electronic structure of FeSe
• Anomalous Fermi surface in FeSe seen by Shubnikov-de Haas oscillation measurements
• Evidence of Andreev bound states as a hallmark of the FFLO phase in $\kappa$-(BEDT-TTF)${}_2$Cu(NCS)${}_2$
• Giant superconducting fluctuations in the compensated semimetal FeSe at the BCS-BEC crossover
• Quantum oscillations and upper critical magnetic field of the iron-based superconductor FeSe
• Switching of magnetic domains reveals evidence for spatially inhomogeneous superconductivity
• Gap structure of FeSe determined by field-angle-resolved specific heat measurements
• Magnetic Lifshitz transition and its consequences in multi-band iron-based superconductors

Cited by in corpus (14)

• Exotic Superconducting States in FeSe-based Materials
• Quantum oscillations in a centrosymmetric skyrmion-hosting magnet GdRu2Si2
• The drastic effect of the impurity scattering on the electronic and superconducting properties of Cu-doped FeSe
• Quasiparticle Nodal Plane in the Fulde-Ferrell-Larkin-Ovchinnikov State of FeSe
• Electronic transport properties and hydrostatic pressure effect of FeSe${}_{0.67}$Te${}_{0.33}$ single crystals free of phase separation
• Vortex-lattice melting and paramagnetic depairing in the nematic superconductor FeSe
• Disorder-robust high-field superconducting phase of FeSe single crystals
• Multi-band description of the upper critical field of bulk FeSe
• Feasibility of a Fulde-Ferrell-Larkin-Ovchinnikov superfluid Fermi atomic gas
• Superconductivity of highly spin-polarized electrons in FeSe probed by ${}^{77}$Se NMR
• Stable non-equilibrium Fulde-Ferrell-Larkin-Ovchinnikov state in a spin-imbalanced driven-dissipative Fermi gas loaded on a three-dimensional cubic optical lattice
• Unusual normal and superconducting state properties observed in hydrothermal Fe1-xSe flakes
• Temperature dependence and limiting mechanisms of the upper critical field of FeSe thin films
• Engineering nonequilibrium superconducting phases in a voltage-driven superconductor under an external magnetic field