Quantum skyrmions and the destruction of long-range antiferromagnetic order in the high-Tc superconductors La2-xSrxCuO4 and YBa2Cu3O6+x
Abstract
We study the destruction of long-range antiferromagnetic order in the high-Tc superconductors La2-xSrxCuO4 and YBa2Cu3O6+x. The CP1-nonlinear sigma model formulation of the two-dimensional quantum Heisenberg antiferromagnet is used for describing the pure system. Dopants are introduced as independent fermions with an appropriate dispersion relation determined by the shape of the Fermi surface. Skyrmion topological defects are shown to be introduced by doping and their energy is used as an order parameter for the antiferromagnetic order. We obtain analytic expressions for the skyrmion energy as a function of doping that allow us to plot, without adjustable parameters, the curves TN(xc)×xc and M(x)×x, for the two compounds, in good quantitative agreement with the experimental data.
- Publication:
-
Physical Review B
- Pub Date:
- September 2001
- DOI:
- 10.1103/PhysRevB.64.092511
- arXiv:
- arXiv:cond-mat/0008186
- Bibcode:
- 2001PhRvB..64i2511M
- Keywords:
-
- 74.72.Bk;
- 74.25.Ha;
- Y-based cuprates;
- Magnetic properties;
- Condensed Matter - Strongly Correlated Electrons;
- Condensed Matter - Superconductivity;
- High Energy Physics - Theory
- E-Print:
- 4 pages, revtex, 5 embeeded figures