Weak – coupling calculation of the gap structure of doped n – leg Hubbard ladders
نویسندگان
چکیده
Weak–coupling calculation of the gap structure of doped n–leg Hubbard ladders Abstract In weak coupling, the spin gap in doped, even, n–leg periodic Hubbard ladders reflects the energy to break a pair into separate quasiparticles. Here we investigate the structure of the gap within a spin–fluctuation exchange approximation. We also calculate the amplitude for removing a singlet pair from two lattice sites separated by a distance (ℓ x , ℓ y), which describes the internal structure of a pair.
منابع مشابه
N-chain Hubbard model in weak coupling
We present a systematic weak-coupling renormalization group ~RG! technique for studying a collection of N coupled one-dimensional interacting electron systems, focusing on the example of N-leg Hubbard ladders. For N52,3, we recover previous results, and find that also more generally broad regions of the phase space of these models are unstable to pairing, usually with approximate d-wave symmetr...
متن کاملHole doped Hubbard ladders
The formation of stripes in six-leg Hubbard ladders with cylindrical boundary conditions is investigated for two different hole dopings, where the amplitude of the hole density modulation is determined in the limits of vanishing DMRG truncation errors and infinitely long ladders. The results give strong evidence that stripes exist in the ground state of these systems for strong but not for weak...
متن کاملSpin ladders with spin gaps: A description of a class of cuprates.
We investigate the magnetic properties of the Cu-O planes in stoichiometric Srn−1Cun+1O2n (n=3,5,7,...) which consist of CuO double chains periodically intergrown within the CuO2 planes. The double chains break up the two-dimensional antiferromagnetic planes into Heisenberg spin ladders with nr = 1 2 (n − 1) rungs and nl = 12 (n + 1) legs and described by the usual antiferromagnetic coupling J ...
متن کاملCu NMR Study of Spin Dynamics in Low - dimensional Spin 1 / 2 Antiferromagnets
63 Cu and 170 nuclear magnetic resonance (NMR) and nuclear quadrupole resonance (NQR) experiments are reported on copper-oxide compounds related to high temperature superconductors that are nearly ideal realizations of spin 1/2 Heisenberg antiferromagnets with different geometries of the magnetic interactions: 1 dimensional spin chains, 2 dimensional planes, two coupled chains (two-leg ladder),...
متن کاملOptical, Photoluminescence and Thermoluminescence Properties Investigation of ZnO and Mn Doped ZnO Nanocrystals
ZnO and ZnO: Mn nanocrystals synthesized via reverse micelle method. The structural properties nanocrystals were investigated by XRD and Transmission electron microscopy (TEM). The XRD results indicate that the synthesized nanocrystals had a pure wurtzite (hexagonal phase) structure. The various optical properties of these nanocrystals such as optical band gap energy, refractive index, dielectr...
متن کامل