First-order ferromagnetic phase transition in the low electronic density regime of a biased graphene bilayer
; Castro, Eduardo V.
Silva, N. A.
; Peres, N. M. R.
Condensed Matter Physics Vol. 20, Nº 33, pp. 33520-1 - 33520-10, August, 2008.
ISSN (print): 1607-324X
ISSN (online): 2224-9079
Journal Impact Factor: 0,488 (in 2008)
Digital Object Identifier: 10.1088/0953-8984/20/33/335207
The phase diagram of a biased graphene bilayer is computed and the existence of a ferromagnetic phase is discussed both in the critical on-site interaction Uc versus doping density and versus temperature. We show that in the ferromagnetic phase the two planes have unequal magnetization and that the electronic density is hole-like in one plane and electron-like in the other. We give evidence for a first-order phase transition between paramagnetic and ferromagnetic phases induced by doping at zero temperature.