1National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, Nanjing 210093
2Chinese Center of Advanced Science and Technology (World Laboratory),P.O. Box 8730, Beijing 100080
Low-Density Ferromagnetism in the Hubbard Model
AN Jin1;GONG Chang-De2,1
1National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, Nanjing 210093
2Chinese Center of Advanced Science and Technology (World Laboratory),P.O. Box 8730, Beijing 100080
Abstract： We study analytically the stability of the saturated ferromagnetic ground state (the Nagaoka state) of the Hubbard model in the low electron density limit with the mean-field approach. We find that the critical Uc is just 4πt, where t is the hopping integral between the nearest neighbours, i.e., when U is larger than 4πt,the paramagnetic state is unstable with respect to the ferromagnetic state, and vice versa.
AN Jin;GONG Chang-De;. Low-Density Ferromagnetism in the Hubbard Model[J]. 中国物理快报, 2001, 18(1): 109-110.
AN Jin, GONG Chang-De,. Low-Density Ferromagnetism in the Hubbard Model. Chin. Phys. Lett., 2001, 18(1): 109-110.
2001, Vol. 18 
