Smith AW, Jaeger HM, Rosenbaum TF, Petrean AM, Kwok WK, Crabtree GW
The James Franck Institute and Department of Physics, The University of Chicago, Chicago, Illinois 60637, USA.
Phys Rev Lett. 2000 May 22;84(21):4974-7. doi: 10.1103/PhysRevLett.84.4974.
We study the vortex phase diagram in untwinned YBCO crystals with columnar defects. These randomly distributed defects are expected to induce a "Bose glass" phase of localized vortices exhibiting a vanishing resistance and Meissner effect for magnetic fields H( perpendicular) transverse to the columns. We directly observe the transverse Meissner effect using a Hall probe array. As predicted, the Meissner state breaks down at temperatures T(s) that decrease linearly as H( perpendicular) increases. However, T(s) lies far below the conventional melting temperature T(m) determined by a vanishing resistivity, suggesting a regime where vortices are effectively localized even when rotated off the columnar defects.
我们研究了具有柱状缺陷的非孪晶YBCO晶体中的涡旋相图。这些随机分布的缺陷预计会诱导出局部涡旋的“玻色玻璃”相，对于垂直于柱状方向的磁场H，该相表现出零电阻和迈斯纳效应。我们使用霍尔探针阵列直接观测横向迈斯纳效应。正如预测的那样，迈斯纳态在温度T(s)下会瓦解，T(s)随着H(垂直)的增加而线性下降。然而，T(s)远低于由电阻率消失所确定的传统熔化温度T(m)，这表明即使涡旋从柱状缺陷处旋转开，它们在该区域仍能有效地被局域化。
