Researchers report a graphene system in which electrons freeze as the temperature rises

Two teams of researchers have independently reported 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. When they tried to explain this, 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 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.