2017 James Clerk Maxwell Medal and Prize

Dr Marcin Mucha-Kruczynski of the University of Bath, for outstanding contributions to the understanding of graphene, in particular groundbreaking studies that have addressed its optical properties, lattice deformations, electronic structure, and electron transport.

Dr Marcin Mucha-Kruczynski’s first publication highlighted a way to visualise the famous Berry phase of Dirac fermions, by demonstrating the sensitivity of angle-resolved photoemission spectroscopy to electron pseudo-spin in graphene materials.

His doctoral studies, awarded the Springer Prize for Excellence in PhD Research, included a prediction of the electronic Raman scattering of bilayer graphene, and the first self-consistent calculation of the band gap induced by electric fields when the material is in a magnetic field.

His later study of the electronic spectrum of bilayer graphene established this material as a unique playground to investigate the relation between band topology and interaction effects. He contributed his theory to the discovery in this crystal of the electron nematic phase – an unusual and rare state in which pointlike electrons spontaneously break rotational symmetry. In another collaboration, he explained the impact of the single-particle Fermi surface topology on interaction-driven transitions between quantum Hall states.

Recently, he has been working on heterostructures of graphene and hexagonal boron nitride. As part of a collaboration, he modelled the effects of lattice incommensurability, and was thus able to interpret the first observation of the fractal electronic spectrum of electrons in 2D in a magnetic field and periodic potential. Such a spectrum, often called Hofstadter’s butterfly, had been unsuccessfully sought for a quarter of a century.

His theoretical framework underpins ongoing studies of this unique regime, and is the first symmetry-based macroscopic model describing the electronic consequences of an incommensurate interface between two 2D crystals – a situation highly unusual for traditional heterostructures but natural for materials glued together by van der Waals forces.

Mucha-Kruczynski has collaborated with experimental groups in the UK and overseas and his works have attracted more than 900 citations.

In the short time since becoming a lecturer at the University of Bath in 2015, he has attracted three PhD students and established an active research group studying the electronic properties of 2D crystals and their heterostructures. He has also given numerous public lectures on his research.