In superconductors possessing both time and inversion symmetries, the Zeeman effect of an external magnetic field can break the time-reversal symmetry, forming a conventional Fulde–Ferrell–Larkin–Ovchinnikov (FFLO) state characterized by Cooper pairings with finite momentum^1,2. In superconductors lacking (local) inversion symmetry, the Zeeman effect may still act as the underlying mechanism of FFLO states by interacting with spin–orbit coupling (SOC). Specifically, the interplay between the Zeeman effect and Rashba SOC can lead to the formation of more accessible Rashba FFLO states that cover broader regions in the phase diagram^3,4,5. However, when the Zeeman effect is suppressed because of spin locking in the presence of Ising-type SOC, the conventional FFLO scenarios are no longer effective. Instead, an unconventional FFLO state is formed by coupling the orbital effect of magnetic fields with SOC, providing an alternative mechanism in superconductors with broken inversion symmetries^6,7,8. Here we report the discovery of such an orbital FFLO state in the multilayer Ising superconductor 2H-NbSe₂. Transport measurements show that the translational and rotational symmetries are broken in the orbital FFLO state, providing the hallmark signatures of finite-momentum Cooper pairings. We establish the entire orbital FFLO phase diagram, consisting of a normal metal, a uniform Ising superconducting phase and a six-fold orbital FFLO state. This study highlights an alternative route to achieving finite-momentum superconductivity and provides a universal mechanism to preparing orbital FFLO states in similar materials with broken inversion symmetries.

在同时具有时间对称性和反演对称性的超导体中，外部磁场的塞曼效应可以打破时间反演对称性，形成传统的富尔德-费雷尔-拉金-奥夫钦尼科夫（FFLO）态，其特征是具有有限动量的库珀对^1,2。在缺乏（局部）反演对称性的超导体中，塞曼效应可能仍然通过与自旋轨道耦合（SOC）相互作用而充当 FFLO 态的基本机制。具体来说，塞曼效应和 Rashba SOC 之间的相互作用可以导致形成更容易接近的 Rashba FFLO 态，覆盖相图中更广泛的区域^3,4,5。然而，当伊辛型 SOC 存在的情况下由于自旋锁定而抑制塞曼效应时，传统的 FFLO 方案不再有效。相反，非常规的 FFLO 状态是通过将磁场的轨道效应与 SOC 耦合而形成的，从而为具有破缺反演对称性的超导体提供了一种替代机制^6,7,8。_{在这里，我们报告了在多层伊辛超导体 2H-NbSe 2}中发现了这种轨道 FFLO 态。输运测量表明，平移和旋转对称性在轨道 FFLO 状态下被破坏，提供了有限动量库珀配对的标志特征。我们建立了整个轨道FFLO相图，由普通金属、均匀伊辛超导相和六重轨道FFLO态组成。这项研究强调了实现有限动量超导性的替代途径，并提供了一种在具有破缺反演对称性的类似材料中制备轨道 FFLO 态的通用机制。