Investigating the size effect on the electrical conductivity at nanoscale with solid spins

Abstract

With the miniaturization of electrical components at nanoscale, the impact of dimension and shape on the electrical properties of the devices plays an important role in the applications. In this work, we used an ensemble of nitrogen-vacancy (NV) centers in diamond to noninvasively investigate the size effect on electric conductivity at nanoscale. The magnetic noise originated from the random movement of electrons in conductors, which is related to the conductivity, was detected by recording the spin relaxation of NV centers. The results indicate that the conductivity increases with the size of devices at the scale of electron mean free path. By further imaging the magnetic noise of the metallic structure with discontinuous thickness, we demonstrated that the spatial distribution of conductance at nanoscale can be revealed with high density NV center arrays. The results can help to understand the electron transport in nanomaterials. This technique can be used to optimize the design of nanoscale electrical devices.