Superconductivity and other phases in graphene multilayers, without twists

The last commentary posted by me in this journal club[1] started with the sentence: The phase diagram of twisted bilayer graphene keeps bringing up surprises. The present commentary can well begin with the same sentence, except that the word twisted is to be removed. Recent experiments have shown superconductivity and correlated phases in graphene trilayers[2], and also in bilayer graphene[3] (superconductivity and correlated phases), and [4, 5] (correlated phases). The experiments have been carried out on systems already studied in the past, and they suggest that carbon compounds admit a non trivial phase diagram without the existence of a complex moiré pattern.