Thorsmølle V K, Averitt R D, Shibauchi T, Hundley M F, Taylor A J
Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
Phys Rev Lett. 2006 Dec 8;97(23):237001. doi: 10.1103/PhysRevLett.97.237001. Epub 2006 Dec 4.
We have used terahertz spectroscopy to measure the Josephson plasma resonance in the superconductor Tl2Ba2CaCu2O8+delta. This allows us to probe the longitudinal ordering of pancake vortices as a function of applied ab-plane current in a 2.5 kG c-axis magnetic field. With increasing current in the low temperature vortex solid phase, we observe a decrease in the interlayer phase coherence consistent with a progressive misalignment of the pancake vortices in neighboring layers. In the high temperature vortex liquid phase, an increase in the longitudinal ordering occurs above a certain threshold current. Our results show evidence of a current-driven coupling-decoupling crossover in the pinned liquid phase.
我们利用太赫兹光谱来测量超导材料Tl2Ba2CaCu2O8+δ中的约瑟夫森等离子体共振。这使我们能够在2.5 kG的c轴磁场中，探究作为施加的ab平面电流函数的饼状涡旋的纵向有序性。在低温涡旋固相状态下，随着电流增加，我们观察到层间相位相干性降低，这与相邻层中饼状涡旋逐渐错位一致。在高温涡旋液相状态下，在一定阈值电流之上，纵向有序性增加。我们的结果显示了在钉扎液相中存在电流驱动的耦合-解耦交叉的证据。
