Department of Physics and Astronomy, Hunter College of City University of New York, 695 Park Avenue, New York, NY 10065-50085, USA.
J Phys Condens Matter. 2010 Apr 28;22(16):165301. doi: 10.1088/0953-8984/22/16/165301. Epub 2010 Mar 30.
We studied the Klein paradox in zigzag (ZNR) and anti-zigzag (AZNR) graphene nanoribbons. Due to the fact that ZNR (the number of lattice sites across the nanoribbon = N is even) and AZNR (N is odd) configurations are indistinguishable when treated by the Dirac equation, we supplemented the model with a pseudo-parity operator whose eigenvalues correctly depend on the sublattice wavefunctions for the number of carbon atoms across the ribbon, in agreement with the tight-binding model. We have shown that the Klein tunneling in zigzag nanoribbons is related to conservation of the pseudo-parity rather than pseudo-spin as in infinite graphene. The perfect transmission in the case of head-on incidence is replaced by perfect transmission at the center of the ribbon and the chirality is interpreted as the projection of the pseudo-parity on momentum at different corners of the Brillouin zone.
我们研究了锯齿形（ZNR）和反锯齿形（AZNR）石墨烯纳米带中的克莱因悖论。由于狄拉克方程处理时 ZNR（纳米带的晶格位置数= N 为偶数）和 AZNR（N 为奇数）的构型无法区分，我们通过引入伪宇称算符来补充模型，其本征值正确地依赖于沿带的碳原子数的子晶格波函数，这与紧束缚模型一致。我们已经表明，锯齿形纳米带中的克莱因隧道与伪宇称的守恒有关，而不是像在无限石墨烯中那样与赝自旋的守恒有关。在迎头入射的情况下，完美透射被取代为在带的中心的完美透射，而手性被解释为在布里渊区的不同角落的动量上的伪宇称的投影。
