2018/08/31 by Tetsuya Takaishi, Kazuhiko Sakakibara, Ikuo Ichinose +1 · 8 citations
Physics and Astronomy · #Advanced Condensed Matter Physics #Antiferromagnetism #Boson #Condensed matter physics #Delocalized electron #Eigenvalues and eigenvectors #Fermion #Gauge theory #Hamiltonian (control theory) #Lattice (music) #Physics #Physics of Superconductivity and Magnetism #Quantum and electron transport phenomena #Quantum mechanics #Spin (aerodynamics) #Spins #cond-mat.dis-nn #cond-mat.str-el
paper · pdf · doi:10.1103/physrevb.98.184204
published in Physical review. B./Physical review. B 98(18) (American Physical Society) · Version to appear in Phys. Rev. B
arxiv created 2018/11/15 · openalex publication_date 2018/11/19 · arxiv updated 2018/11/21 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We study the (de)localization phenomena of one-component lattice fermions in spin backgrounds. The O(3) classical spin variables on sites fluctuate thermally through the ordinary nearest-neighbor coupling. Their complex two-component (CP1-Schwinger boson) representation forms a composite U(1) gauge field on bond, which acts on fermions as a fluctuating hopping amplitude in a gauge invariant manner. For the case of antiferromagnetic (AF) spin coupling, the model has a close relationship with the t\ensuremath-J model of strongly correlated electron systems. We measure the unfolded level spacing distribution of fermion energy eigenvalues and the participation ratio of energy eigenstates. The results for AF spin couplings suggest a possibility that, in two dimensions, all the energy eigenstates are localized. In three dimensions, we find that there exists a mobility edge, and we estimate the critical temperature TLD(\ensuremathδ) of the localization-delocalization transition at the fermion concentration \ensuremathδ.