• 文献标题:   Valley-based Cooper pair splitting via topologically confined channels in bilayer graphene
  • 文献类型:   Article
  • 作  者:   SCHROER A, SILVESTROV PG, RECHER P
  • 作者关键词:  
  • 出版物名称:   PHYSICAL REVIEW B
  • ISSN:   2469-9950 EI 2469-9969
  • 通讯作者地址:   Tech Univ Carolo Wilhelmina Braunschweig
  • 被引频次:   13
  • DOI:   10.1103/PhysRevB.92.241404
  • 出版年:   2015

▎ 摘  要

Bilayer graphene hosts valley-chiral one-dimensional modes at domain walls between regions of different interlayer potential or stacking order. When such a channel is close to a superconductor, the two electrons of a Cooper pair, which tunnel into it, move in opposite directions because they belong to different valleys related by the time-reversal symmetry. This kinetic variant of Cooper pair splitting requires neither Coulomb repulsion nor energy filtering but is enforced by the robustness of the valley isospin in the absence of atomic-scale defects. We derive an effective normal/superconducting/normal (NSN) model of the channel in proximity to an s-wave superconductor, calculate the conductance of split and spin-entangled pairs, and interpret it as a result of local Andreev reflection, in contrast to the widespread identification of Cooper pair splitting with crossed Andreev reflection in an NSN geometry.