Two teams of researchers have independently found that
there exists a certain type of graphene system where electrons
freeze as the temperature rises. The first team, with members from
Israel, the U.S. and Japan, found that placing one layer of
graphene atop another and then twisting the one on top resulted in
a graphene state in which the electrons would freeze as
temperatures rose. And in attempting to explain what they observed,
they discovered that the entropy of the near-insulating phase was
approximately half of what would be expected from free-electron
spins. The second team, with members from the U.S., Japan and
Israel, found the same graphene system and in their investigation
to understand their observations, they noted that a large magnetic
moment arose in the insulator. Both teams have published their
results in the journal Nature. Biao Lian with Princeton University
has published a News and Views piece outlining the work by both
teams in the same journal issue.
