论文标题
通过磁场响应对电场对超导体的揭示机制影响
Unveiling Mechanisms of Electric Field Effects on Superconductors by Magnetic Field Response
论文作者
论文摘要
我们证明，超导铝纳米桥可以通过静电控件完全抑制临界超电流的状态。在存在静电门控的情况下，探测平面磁场的磁场响应可以公布主要导致超导电场效应的机制。值得注意的是，我们发现一个独立于其方向的磁场对关键电场的影响较弱，该磁场可以识别从超导状态到一个消失的临界超流量的阶段的过渡。该观察结果表明，在电场和超导顺序参数的振幅之间没有直接耦合，或通过涡旋生成$2π$ - 相滑。在微观模型中描述了在存在静电门控的情况下观察到的磁场效应，其中电场稳定了空间均匀的带间$π$ - 相。这种固有的超导相位重排可以解释超电流的抑制，以及临界磁场对电场的弱依赖性。
We demonstrate that superconducting aluminium nano-bridges can be driven into a state with complete suppression of the critical supercurrent via electrostatic gating. Probing both in- and out-of-plane magnetic field responses in the presence of electrostatic gating can unveil the mechanisms that primarily cause the superconducting electric field effects. Remarkably, we find that a magnetic field, independently of its orientation, has only a weak influence on the critical electric field that identifies the transition from the superconducting state to a phase with vanishing critical supercurrent. This observation points to the absence of a direct coupling between the electric field and the amplitude of the superconducting order parameter or $2π$-phase slips via vortex generation. The magnetic field effect observed in the presence of electrostatic gating is described within a microscopic model where a spatially uniform inter-band $π$-phase is stabilized by the electric field. Such an intrinsic superconducting phase rearrangement can account for the suppression of the supercurrent, as well as for the weak dependence of the critical magnetic fields on the electric field.
