Department of Physics and Astronomy, Georgia State University, Atlanta, Georgia 30303, USA.
Phys Rev Lett. 2010 Jul 16;105(3):036801. doi: 10.1103/PhysRevLett.105.036801. Epub 2010 Jul 13.
Here we report from our theoretical studies that, in biased bilayer graphene, one can induce phase transitions from an incompressible fractional quantum Hall state to a compressible state by tuning the band gap at a given electron density. The nature of such phase transitions is different for weak and strong interlayer coupling. Although for strong coupling more levels interact there is a lesser number of transitions than for the weak coupling case. The intriguing scenario of tunable phase transitions in the fractional quantum Hall states is unique to bilayer graphene and has never before existed in conventional semiconductor systems.
在这里，我们从理论研究中报告，在有偏双层石墨烯中，通过在给定电子密度下调节能带隙，可以诱导从不可压缩分数量子霍尔态到可压缩态的相变。对于弱和强层间耦合，这种相变的性质是不同的。尽管对于强耦合，更多的能级相互作用，但比弱耦合情况的转变数量更少。在分数量子霍尔态中，这种可调谐相变的有趣情况是双层石墨烯所独有的，在传统半导体系统中从未存在过。
