摘要
Based on the mean-field theory,we investigate the thermodynamic properties of the two-dimensional(2D)charged spin-1/2 Fermi gas.Lande′factor g is introduced to measure the strength of the paramagnetic effect.There is a competition between diamagnetism and paramagnetism in the system.The larger the Lande′factor,the smaller the entropy and specific heat.Diamagnetism tends to increase the entropy,while paramagnetism leads to the decrease of the entropy.We find that there exists a critical value of Lande′factor for the transition point due to the competition.The entropy of the system increases with the magnetic field when g<0.58.With the growth of paramagnetism,when g>0.58,the entropy first decreases with the magnetic field,then reaches a minimum value,and finally increases again.Both the entropy and specific heat increase with the temperature,and no phase transition occurs.The specific heat tends to a constant value at the hightemperature limit,and it approaches to zero at very low temperatures,which have been proved by the analytical calculation.
作者
杨家营
刘旭
秦吉红
郭怀明
Jia-Ying Yang;Xu Liu;Ji-Hong Qin;Huai-Ming Guo(Department of Physics,University of Science and Technology Beijing,Beijing 100083,China;Institute of Theoretical Physics,University of Science and Technology Beijing,Beijing 100083,China;Department of Physics,Beihang University,Beijing 100191,China)
基金
supported by the National Natural Science Foundation of China(Grant No.11774019)
the Fundamental Research Funds for the Central Universities,China(Grant No.FRF-BR-16-014A)。