2001/12/24 by Avinash Singh, Haranath Ghosh · 1 citation
Materials Science · Physics and Astronomy · #Advanced Condensed Matter Physics #Magnetic and transport properties of perovskites and related materials #Physics of Superconductivity and Magnetism #cond-mat.str-el
paper · pdf · doi:10.1103/physrevb.65.134414
published as Phys. Rev. B vol. 65, 134414 (2002) · 10 pages, 8 figures
arxiv created 2001/12/24 · openalex publication_date 2002/03/19 · arxiv updated 2009/11/30 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
The next-nearest-neighbor hopping term t^\ensuremath' is shown to stabilize the antiferromagnetic (AF) state of the doped Hubbard model with respect to transverse perturbations in the order parameter by strongly suppressing the intraband particle-hole processes. For a fixed sign of t^\ensuremath', this stabilization is found to be significantly different for electron and hole doping, which qualitatively explains the observed difference in the degree of robustness of the AF state in the electron-doped (Nd_2\ensuremath-xCexCuO4) and hole-doped (La_2\ensuremath-xSrxCuO4) cuprates. The t^\ensuremath'\ensuremath-U phase diagram is obtained for both signs of the t^\ensuremath' term, showing the different regions of stability and instability of the doped antiferromagnet. Doping is shown to suppress the t^\ensuremath'-induced frustration due to the competing interaction J^\ensuremath'. A study of transverse spin fluctuations in the metallic AF state reveals that the decay of magnons into particle-hole excitations yields an interesting low-energy result \ensuremathΓ\ensuremath∼\ensuremathω for magnon damping.