A Family of Finite-Temperature Electronic Phase Transitions in Graphene Multilayers

Thickness matters in graphene stacks If you stack graphene monolayers on top of each other, the number of layers will affect the properties of the material. Intuitively, one would expect that as the stack becomes thicker, the results will converge as the sample starts to resemble graphite. Nam et al. measured the conductance of graphene multilayers of increasing thickness. Studying samples up to seven layers thick, they found that in all of them, electronic correlations caused a phase transition at a nonzero critical temperature. However, the critical temperature, as well as the nature of the low-temperature state, depended strongly on the number of layers. This unexpectedly persistent dependence showed no signs of slowing down and will motivate further theoretical and experimental work. Science , this issue p. 324