Tuning the valley and chiral quantum state of Dirac electrons in van der Waals heterostructures
Abstract
Chirality is a fundamental property of electrons with the relativistic spectrum found in graphene and topological insulators. It plays a crucial role in relativistic phenomena, such as Klein tunneling, but it is difficult to visualize directly. Here we report the direct observation and manipulation of chirality and pseudospin polarization in the tunneling of electrons between two almost perfectly aligned graphene crystals. We use a strong in-plane magnetic field as a tool to resolve the contributions of the chiral electronic states that have a phase difference between the two components of their vector wavefunction. Our experiments not only shed light on chirality, but also demonstrate a technique for preparing graphene's Dirac electrons in a particular quantum chiral state in a selected valley.
Keywords
Cite
@article{arxiv.1608.02411,
title = {Tuning the valley and chiral quantum state of Dirac electrons in van der Waals heterostructures},
author = {J. R. Wallbank and D. Ghazaryan and A. Misra and Y. Cao and J. S. Tu and B. A. Piot and M. Potemski and S. Pezzini and S. Wiedmann and U. Zeitler and T. L. M. Lane and S. V. Morozov and M. T. Greenaway and L. Eaves and A. K. Geim and V. I. Fal'ko and K. S. Novoselov and A. Mishchenko},
journal= {arXiv preprint arXiv:1608.02411},
year = {2016}
}
Comments
26 pages, 13 figures