Stern A, Girvin S M, MacDonald A H, Ma N
Department of Condensed Matter Physics, Weizmann Institute, Rehovet, Israel.
Phys Rev Lett. 2001 Feb 26;86(9):1829-32. doi: 10.1103/PhysRevLett.86.1829.
Spielman et al. [Phys. Rev. Lett. 84, 5808 (2000] recently observed a large and sharp Josephson-like zero-bias peak in the tunnel conductance of a bilayer system in a quantum Hall ferromagnet state. We argue that disorder-induced topological defects in the pseudospin order parameter limit the peak size and destroy the predicted Josephson effect. We predict that the peak would be split and shifted by an in-plane magnetic field in a way that maps the dispersion relation of the ferromagnet's Goldstone mode. We also predict resonant structures in the dc I-V characteristic under bias by an ac electric field.
斯皮尔曼等人[《物理评论快报》84, 5808 (2000)]最近在量子霍尔铁磁体状态的双层系统的隧道电导中观测到一个大且尖锐的类似约瑟夫森的零偏置峰。我们认为，赝自旋序参量中由无序诱导的拓扑缺陷限制了峰的大小并破坏了预测的约瑟夫森效应。我们预测，该峰会被面内磁场分裂并移动，其方式映射了铁磁体戈德斯通模的色散关系。我们还预测，在交流电场偏置下的直流I-V特性中会出现共振结构。
