High temperature quantum transport in graphene/hexagonal boron nitride heterostructures

Roshan Krishna Kuma
April 19th, 2018 ROSHAN KRISHNA KUMAR Lancaster University

Graphene has proven itself a unique system for electron transport studies, with a number of novel phenomena and device architectures appearing in experiments over the past decade. In the case of quantum transport, measurements are typically focussed at liquid helium temperatures in order to reduce vibrations and preserve coherence. In our experiments, we instead demonstrate several novel transport effects intrinsic to graphene that manifest only at high-temperatures (100 – 300 K). In particular, we studied Hofstadter butterfly physics in graphene superlattices in this previously unexplored regime. Here, we found a new class of robust quantum oscillations1 that persist to 400 K even in fields as low as 3 T. The result provides crucial, fundamental understanding into peculiar behaviour of electrons in crystals and sets straight the physics underlying Hofstadter butterflies2,3. In my talk I will summarise the key experimental findings and explain its significance in relation to previous works on graphene superlattices.

Seminar, April 19, 2018, 12:00. ICFO’s Seminar Room

Hosted by Prof. Frank Koppens