biostudies-literatureCho CWResearch Grants Council, University Grants Committee (RGC, UGC)7599https://www.ebi.ac.uk/biostudies/studies/S-EPMC12356947biostudies-literatureUnknown16(1)The Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) state is an unusual superconducting phase that survives beyond the Pauli paramagnetic limit through spatial modulation of the order parameter. An even more exotic variant-the orbital FFLO state-was recently reported in thin flakes of 2H-NbSe₂, involving the interplay of Ising spin-orbit coupling and orbital pair breaking. Here, we report thermodynamic signatures consistent with an orbital FFLO state in bulk 2H-NbSe₂, based on high-resolution magnetization and torque measurements under strictly parallel to the NbSe₂ basal plane. In the magnetic phase diagram, a crossover to a first-order transition appears above 3 T and disappears with slight field misalignment, indicating field-angle dependent Pauli-limited behaviNature communicationsEvidence for orbital Fulde-Ferrell-Larkin-Ovchinnikov state in the bulk limit of 2H-NbSe<sub>2</sub>.PMC12356947GRF-16303820Abdel-Hafiez MAllan ARPark JPark KChui SHLo KTNg CYYuan NFQLortz RCho CWLortz TTCho BfalseEvidence for orbital Fulde-Ferrell-Larkin-Ovchinnikov state in the bulk limit of 2H-NbSe<sub>2</sub>.The Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) state is an unusual superconducting phase that survives beyond the Pauli paramagnetic limit through spatial modulation of the order parameter. An even more exotic variant-the orbital FFLO state-was recently reported in thin flakes of 2H-NbSe₂, involving the interplay of Ising spin-orbit coupling and orbital pair breaking. Here, we report thermodynamic signatures consistent with an orbital FFLO state in bulk 2H-NbSe₂, based on high-resolution magnetization and torque measurements under strictly parallel to the NbSe₂ basal plane. In the magnetic phase diagram, a crossover to a first-order transition appears above 3 T and disappears with slight field misalignment, indicating field-angle dependent Pauli-limited behavi2025-01-01T00:00:00Z2025 Aug2026-04-30T14:39:28.468Z2026-04-07T16:03:25.315ZS-EPMC123569474081732910.1038/s41467-025-62223-w