Dresden 2009 – wissenschaftliches Programm

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TT: Fachverband Tiefe Temperaturen

TT 26: Transport: Graphene and Carbon Nanotubes

TT 26.14: Vortrag

Mittwoch, 25. März 2009, 18:00–18:15, HSZ 03

Coupling between chirality and pseudospin in a 2D Dirac fermion semi-confinement: New type of polarization and electronic functionalities — •Grigory Tkachov and Martina Hentschel — Max Planck Institute for the Physics of Complex Systems, Dresden

We introduce a novel type of polarization - chiral pseudospin polarization (CPP) - that represents a nonmagnetic analogue of electron spin polarization [1]. It can be realized in two-dimensional carbon or semiconductor systems exhibiting massless Dirac fermions of two opposite chiralities. The CPP occurs as a boundary effect arising from a correlation between the chirality and effective spin degrees of freedom, which is unique to time-reversal invariant Dirac fermion confinement. The CPP can be probed by tunneling, resulting in a zero-bias conductance anomaly and a singular particle-hole asymmetric local density of states. We use our findings to interpret recent scanning tunneling experiments on monoatomic graphite steps and outline possible applications motivated by the search for new functionalities brought by Dirac quasiparticles into nanoelectronics.

[1] G. Tkachov and M. Hentschel, arXiv: 0810.0632.