Carbon nanotube as a local drag sensor

We report a Columb drag measurement in a carbon nanotube (CNT) and graphene hybrid device. In this device, the CNT and graphene serve as a 1D and 2D electronic system respectively and are separated by a thin hexagonal boron nitride (h-BN). By flowing a drive current in one conductor, due to electron-electron interactions, a drag voltage is developed in the other conductor. In the case where a current is applied to graphene, the CNT can act as a local drag sensor that probes the microscopic effects of electronic interactions hidden in graphene. We demonstrate this drag sensor capability by applying a magnetic field in graphene and show the transition from compressible states to incompressible states.