Jarlborg T
Département de Physique de la Matière Condensée, University of Geneva, 24 Quai Ernest-Ansermet, CH-1211 Geneva 4, Switzerland.
J Phys Condens Matter. 2009 Apr 8;21(14):142202. doi: 10.1088/0953-8984/21/14/142202. Epub 2009 Mar 5.
An understanding of spin excitations in cuprates is essential since the mechanism of high-T(C) superconductivity might be linked to spin fluctuations. Band calculations for 'one-dimensional' unit cells of La(2)CuO(4) show larger coupling (spin-phonon coupling, SPC) between anti-ferromagnetic spin waves and O-phonons than for Cu- or La-phonons. When this result is applied to a two-dimensional, free-electron like band, it leads to an 'hourglass' shape of the spin excitation spectrum, as in recent experiments. Isotope shifts and doping dependences of the excitations are discussed.
理解铜酸盐中的自旋激发至关重要，因为高温超导机制可能与自旋涨落有关。对La₂CuO₄“一维”晶胞的能带计算表明，反铁磁自旋波与O声子之间的耦合（自旋 - 声子耦合，SPC）比与Cu或La声子之间的耦合更强。当将此结果应用于二维类自由电子能带时，会导致自旋激发谱呈“沙漏”形状，正如最近的实验所示。文中还讨论了激发的同位素位移和掺杂依赖性。
