Investigation of magnetic isotope effect in high-Tc superconductors

为了揭示高温超导铜酸盐中Cooper对形成的微观机制，我们用非弹性中子散射研究了Ni掺杂对自旋动力学的影响。我们发现沙漏形色散的腰部能量，E&lt；cross。向低能方向移动，与T_c成线性关系，类似于BCS型超导体中的同位素效应。我们的研究结果表明，E&lt；cross&gt；附近的反铁磁自旋涨落对高T_c铜酸盐中Cooper对的形成起着重要作用。

In order to reveal microscopic mechanism of the formation of Cooper pairs in high transition temperature (T_c) superconducting cuprates, we have investigated Ni-doping effect on spin dynamics by inelastic neutrons scattering. We have found that the waist energy of the hourglass shaped dispersion, E_<cross>. shift to lower energies with holding linear relationship to T_c, which is analogous to the isotope effect in BCS-type superconductors. Our findings indicate that antiferromagnetic spin fluctuations near E_<cross> play an important role on the formation of Cooper pairs in high-T_c cuprates.