Spectroscopic Evidence for Orbital FFLO State in 2H-NbSe2
Researchers have reported significant spectroscopic evidence for a first-order phase transition within the superconducting state of multilayer 2H-NbSe2, interpreted as thermodynamic proof of the orbital Fulde-Ferrell-Larkin-Ovchinnikov (orb-FFLO) state. Published in Nature Communications, the study utilizes tunneling spectroscopy under an in-plane magnetic field to reveal a sudden enhancement of the superconducting gap accompanied by prominent hysteresis. This transition occurs well below the upper critical field and vanishes when the magnetic field tilts slightly away from the in-plane direction, showing high sensitivity to disorder. The team constructed a comprehensive phase diagram mapping the transition against magnetic field, temperature, and sample thickness. These experimental observations align with theoretical models comparing the energetics of uniform Ising superconductors and the orb-FFLO state. This finding addresses a long-standing lack of thermodynamic demonstration for this exotic dissipationless state, marking a crucial advancement in understanding complex superconducting phenomena and phase transitions in two-dimensional materials.
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Spectroscopic Evidence for Orbital FFLO State in 2H-NbSe2
Researchers have reported significant spectroscopic evidence for a first-order phase transition within the superconducting state of multilayer 2H-NbSe2, interpreted as thermodynamic proof of the orbital Fulde-Ferrell-Larkin-Ovchinnikov (orb-FFLO) state. Published in Nature Communications, the study utilizes tunneling spectroscopy under an in-plane magnetic field to reveal a sudden enhancement of the superconducting gap accompanied by prominent hysteresis. This transition occurs well below the upper critical field and vanishes when the magnetic field tilts slightly away from the in-plane direction, showing high sensitivity to disorder. The team constructed a comprehensive phase diagram mapping the transition against magnetic field, temperature, and sample thickness. These experimental observations align with theoretical models comparing the energetics of uniform Ising superconductors and the orb-FFLO state. This finding addresses a long-standing lack of thermodynamic demonstration for this exotic dissipationless state, marking a crucial advancement in understanding complex superconducting phenomena and phase transitions in two-dimensional materials.
Nature Communications