A pair of researchers, one with Peking University, the other with Princeton University, has found that the parameters of twisted-graphene's excitation spectra correspond directly to attributes of the heavy fermion model. In their paper published in the journal Physical Review Letters, Zhi-Da Song and B. Andrei Bernevig describe building a model to show aspects of the Bistritzer-MacDonald model and then used it to demonstrate characteristics of twisted bilayer graphene. Aline Ramires with the Paul Scherrer Institute has published a News & Views piece in the journal Nature outlining the work by Bernevig and Song.