C-axis magnetoresistance in epitaxially grown multilayer graphene

Magnetoresistance, the change in electrical resistance of a solid-state system as a function of an external magnetic field, is a key effect in condensed matter physics both for fundamental understanding of charge transport phenomena as well as immense commercial implications. Artificial layered structures, such as metallic or metal-insulator multilayers often exhibit ``giant magnetoresistance'' or ``tunnel magnetoresistance'' effects that are exploited in various state-of-the-art data storage and magnetic field sensing devices.. Graphite is a naturally occurring layered structure in which graphene layers are stacked up on each other. Magnetoresistance in graphitic systems has drawn significant attention in recent years due to the unique crystal structures of these materials, which often lead to novel physics. In this work we consider epitaxial multilayer graphene on nickel and studied c-axis charge transport when the magnetic field is applied normal to the graphene plane. We show that the electrical resistance measured across the graphene stack on nickel can be reduced by two orders of magnitude by applying a relatively small magnetic field of few kilogausses normal to the layer plane. This feature persists even at room temperature and is far stronger than any other magnetoresistance effect reported to date for comparable temperature and field conditions. Existence of such effect makes multilayer graphene an attractive platform for magnetic field sensing, data storage and exploration of fundamental insights into graphene physics.