首页|Dynamical t/U Expansion of the Doped Hubbard Model
Dynamical t/U Expansion of the Doped Hubbard Model
扫码查看
点击上方二维码区域，可以放大扫码查看
原文链接
万方数据
维普
We construct a new U(1)slave-spin representation for the single-band Hubbard model in the large-U limit.The mean-field theory in this representation is more amenable to describe both the spin-charge-separation physics of the Mott insulator at half-filling and the strange metal behavior at finite doping.By employing a dynamical Green's function theory for slave spins,we calculate the single-particle spectral function of electrons.The result is comparable to that in dynamical mean field theories.We then formulate a dynamical t/U expansion for the doped Hubbard model that reproduces the mean-field results at the lowest order of expansion.To the next order of expansion,it naturally yields an effective low-energy theory of a t-J model for spinons self-consistently coupled to an XXZ model for the slave spins.We show that the superexchange J is renormalized by doping,in agreement with the Gutzwiller approximation.Surprisingly,we find a new ferromagnetic channel of exchange interactions which survives in the infinite U limit,as a manifestation of the Nagaoka ferromagnetism.
丁文新、俞榕
展开 >
School of Physics and Material Science,Anhui University,Hefei 230601,China
Kavli Institute for Theoretical Sciences,University of Chinese Academy of Sciences,Beijing 100190,China
Physics Department and Beijing Key Laboratory of Opto-electronic Functional Materials and Micro-nano Devices,Renmin University,Beijing 100872,China
Startup Fund of Anhui UniversityKavli Institute for Theoretical SciencesNational Key Research and Development Program of China国家自然科学基金国家自然科学基金
万方数据
维普
