库仑拖曳是指当电流通过一层导电层时，会在邻近且电学隔离的另一层中产生电压，这一 效应完全由载流子之间的层间库仑相互作用引起。该现象已在多种体系中得到广泛研究，包括平 行纳米线、双量子阱以及双层石墨烯。在本工作中，我们报道了一种新型体系中库仑拖曳的观测 结果，该体系由两层石墨烯组成，层间在同一平面内横向分隔 30 nm，表现出与垂直石墨烯异质 结构不同的行为。实验结果显示，在施加垂直磁场时可在相邻的石墨烯边缘处出现明显的负拖曳 电阻，当通过栅压将两层石墨烯的载流子浓度调至电荷中性点时，负拖曳达到最大值。本工作建 立了一个分立且空间上邻近的量子霍尔边缘系统，为探索一维体系间的电子相互作用物理提供了 新的实验平台。

Coulomb drag refers to the phenomenon in which a current driven through one conducting layer induces a voltage nearby, electrically isolated layer sorely through interlayer Coulomb interactions between charge carriers. It has been extensively studied in various systems, including parallel nanowires, double quantum wells, and double-layer graphene. Here, we report the observation of Coulomb drag in a novel system consisting of two graphene layers separated laterally by a 30 nm gap within the material plane, exhibiting behavior distinct from that in vertical graphene heterostructures. Our experiments reveal pronounced negative drag resistances under an out-of-plane magnetic field at the quantum Hall edges, reaching a maximum when the carrier densities in both graphene layers are tuned to the charge neutrality point via gate voltages. Our work establish two separate and spatially closed quantum Hall edge modes as a new platform to explore electronic interaction physics between one dimensional systems.