2017/01/16 by Michele Fabrizio
Mathematics · Physics and Astronomy · #Electron #Hamiltonian (control theory) #Hubbard model #Lattice (music) #Mathematics #Physics #Physics of Superconductivity and Magnetism #Quantum #Quantum and electron transport phenomena #Quantum mechanics #Statistical physics #Strongly correlated material #Theoretical and Computational Physics #Uncorrelated #Wave function #cond-mat.str-el
paper · pdf · doi:10.1103/physrevb.95.075156
published as Phys. Rev. B 95, 075156 (2017) · 17 pages
arxiv created 2017/01/16 · openalex publication_date 2017/02/28 · arxiv updated 2017/03/08 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We present a simple scheme to evaluate linear response functions including quantum fluctuation corrections on top of the Gutzwiller approximation. The method is derived for a generic multiband lattice Hamiltonian without any assumption about the dynamics of the variational correlation parameters that define the Gutzwiller wavefunction, and which thus behave as genuine dynamical degrees of freedom that add on those of the variational uncorrelated Slater determinant. We apply the method to the standard half-filled single-band Hubbard model. We are able to recover known results, but, as by-product, we also obtain few novel ones. In particular, we show that quantum fluctuations can reproduce almost quantitatively the behaviour of the uniform magnetic susceptibility uncovered by dynamical mean field theory, which, though enhanced by correlations, is found to be smooth across the paramagnetic Mott transition. By contrast, the simple Gutzwiller approximation predicts that susceptibility to diverge at the transition.