Eremin M, Rigamonti A
Department of Physics "A. Volta," University of Pavia and Unita' INFM, Via Bassi 6, I-7100 Pavia, Italy.
Phys Rev Lett. 2002 Jan 21;88(3):037002. doi: 10.1103/PhysRevLett.88.037002. Epub 2002 Jan 2.
The spin-freezing process in underdoped cuprate superconductors, observed most by NMR-NQR relaxation and muon spin rotation and sometimes interpreted as coexistence of antiferromagnetic and superconducting states, is generally thought to result from randomly distributed magnetic moments related to charge inhomogeneities (possibly stripes) which exhibit slowing down of their fluctuations on cooling below T(c). Instead, we describe the experimental findings as due to fluctuating magnetic fields caused by sliding motions of orbital currents coexisting with d-wave superconducting state. A direct explanation of the experimental results, in underdoped Y2-xCaxBa2Cu3O6.1 and La2-xSrxCuO4, is thus given in terms of freezing of orbital current fluctuations, and mean squared amplitudes of the related internal magnetic fields are estimated.
在欠掺杂铜酸盐超导体中的自旋冻结过程，通过核磁共振 - 核四极共振弛豫和μ子自旋旋转观察到的情况最为明显，有时被解释为反铁磁态和超导态的共存，一般认为这是由与电荷不均匀性（可能是条纹）相关的随机分布磁矩导致的，这些磁矩在冷却至低于Tc时其涨落会减慢。相反，我们将实验结果描述为与d波超导态共存的轨道电流滑动运动所引起的波动磁场导致的。因此，根据轨道电流涨落的冻结，对欠掺杂的Y2 - xCaxBa2Cu3O6.1和La2 - xSrxCuO4中的实验结果给出了直接解释，并估计了相关内部磁场的均方振幅。
