Hybrid quantum materials allow for quantum phases that otherwise do not exist in nature^1,2. For example, a one-dimensional topological superconductor with Majorana states bound to its ends can be realized by coupling a semiconductor nanowire to a superconductor in the presence of a strong magnetic field^3,4,5. However, the applied magnetic fields are detrimental to superconductivity, and constrain device layout, components, materials, fabrication and operation⁶. Early on, an alternative source of Zeeman coupling that circumvents these constraints—using a ferromagnetic insulator instead of an applied field—was proposed theoretically⁷. Here, we report transport measurements in hybrid nanowires using epitaxial layers of superconducting Al and the ferromagnetic insulator EuS on semiconducting InAs nanowires. We infer a remanent effective Zeeman field exceeding 1 T and observe stable zero-bias conductance peaks in bias spectroscopy at zero applied field, consistent with topological superconductivity. Hysteretic spectral features in applied magnetic field support this picture.

混合量子材料允许在自然^1,2中不存在的量子相。例如，可以通过在强磁场^3,4,5的存在下将半导体纳米线耦合到超导体来实现将马约拉那邦绑定到其末端的一维拓扑超导体。但是，施加的磁场不利于超导性，并限制了器件的布局，组件，材料，制造和操作⁶。早期，理论上提出了使用铁磁绝缘体代替外加磁场来克服这些限制的另一种塞曼耦合源⁷。在这里，我们报告了在半导体InAs纳米线上使用超导Al和铁磁绝缘体EuS的外延层在混合纳米线中进行的传输测量。我们推断出超过1 T的剩余有效Zeeman场，并在零施加场的偏压光谱中观察到稳定的零偏置电导峰，这与拓扑超导性一致。外加磁场中的磁滞频谱特征支持此图像。