2006/05/17 by Jung Hoon Han, Han, Jung Hoon, Chenglong Jia +1
Engineering · Physics and Astronomy · #Advanced Materials and Mechanics #FOS: Physical sciences #Strongly Correlated Electrons (cond-mat.str-el) #Superconductivity (cond-mat.supr-con) #cond-mat.str-el #cond-mat.supr-con
paper · pdf · doi:10.48550/arxiv.cond-mat/0605426
arxiv created 2006/05/17 · openalex publication_date 2006/05/17 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
A phase diagram of two Mott-Hubbard planes interacting with a short-range Coulomb repulsion is presented. Considering the case of equal amount of doping by holes in one layer as electrons in the other, a holon-doublon inter-layer exciton formation is shown to be a natural consequence of Coulomb attraction. Quasiparticle spectrum is gapped and incoherent below a critical doping δc due to the formation of excitons. A spin liquid insulator (SLI) phase is thus realized without the lattice frustration. The critical value δc sensitively depends on the inter-layer interaction strength. In the tJ model description of each layer with the d-wave pairing, δc marks the crossover between SLI and d-wave superconductor. The SLI phase, despite being non-superconducting and charge-gapped, still shows electromagnetic response similar to that of a superfluid due to the exciton transport. Including antiferromagnetic order in the tJ model introduces magnetically ordered phases at low doping and pushes the spin liquid phase to a larger inter-layer interaction strength and higher doping concentrations.