TY  - JOUR 
T1  - Berry's phase in the two-level model
JO  - Brazilian Journal of Physics
A1  - Aguiar Pinto, A.C.
A1  - Moutinho, M.
A1  - Thomaz, M.T.
SN  - 0103-9733
UL  - 10.1590/S0103-97332009000300016
VL  - 39 
Y1  - 2009
PB  - Brasil 
ER  -