Surface Fermi arcs (SFAs), the unique open Fermi-surfaces (FSs) discovered recently in topological Weyl semimetals (TWSs), are unlike closed FSs in conventional materials and can give rise to many exotic phenomena, such as anomalous SFA-mediated quantum oscillations, chiral magnetic effects, three-dimensional quantum Hall effect, non-local voltage generation and anomalous electromagnetic wave transmission. Here, by using in-situ surface decoration, we demonstrate successful manipulation of the shape, size and even the connections of SFAs in a model TWS, NbAs, and observe their evolution that leads to an unusual topological Lifshitz transition not caused by the change of the carrier concentration. The phase transition teleports the SFAs between different parts of the surface Brillouin zone. Despite the dramatic surface evolution, the existence of SFAs is robust and each SFA remains tied to a pair of Weyl points of opposite chirality, as dictated by the bulk topology.

表面费米弧（SFA）是最近在拓扑Weyl半金属（TWS）中发现的独特的开放费米表面（FSs），与常规材料中的封闭FS不同，它可以引起许多外来现象，例如异常SFA介导的量子振荡，手性磁效应，三维量子霍尔效应，非局部电压生成和异常电磁波传输。在这里，通过使用原位在表面装饰中，我们证明了在模型TWS，NbAs中成功地操纵了SFA的形状，大小甚至其连接，并观察了它们的演变，这导致了不寻常的拓扑Lifshitz跃迁，而不是由载流子浓度的变化引起的。相变在表面布里渊区的不同部分之间传送SFA。尽管表面发生了戏剧性的变化，但SFA的存在仍然很牢固，并且每个SFA都与一对手性相反的Weyl点保持联系，这由本体拓扑结构决定。