Zhu Zheng, Sheng D N, Sodemann Inti
Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA.
Department of Physics and Astronomy, California State University, Northridge, California 91330, USA.
Phys Rev Lett. 2020 Mar 6;124(9):097604. doi: 10.1103/PhysRevLett.124.097604.
We develop a proposal to realize a widely tunable and clean quantum phase transition in bilayer graphene between two paradigmatic fractionalized phases of matter: the Moore-Read fractional quantum Hall state and the composite Fermi liquid metal. This transition can be realized at total fillings ν=±3+1/2 and the critical point can be controllably accessed by tuning either the interlayer electric bias or the perpendicular magnetic field values over a wide range of parameters. We study the transition numerically within a model that contains all leading single particle corrections to the band structure of bilayer graphene and includes the fluctuations between the n=0 and n=1 cyclotron orbitals of its zeroth Landau level to delineate the most favorable region of parameters to experimentally access this unconventional critical point. We also find evidence for a new anisotropic gapless phase stabilized near the level crossing of n=0/1 orbits.
我们提出了一项建议，以在双层石墨烯中实现两个典型的分数化物质相之间广泛可调且纯净的量子相变：摩尔-里德分数量子霍尔态和复合费米液体金属。这种相变可以在总填充因子ν = ±3 + 1/2时实现，并且通过在广泛的参数范围内调节层间电偏置或垂直磁场值，可以可控地达到临界点。我们在一个模型中对该相变进行了数值研究，该模型包含了对双层石墨烯能带结构的所有主要单粒子修正，并包括其零朗道能级中n = 0和n = 1回旋轨道之间的涨落，以描绘出通过实验访问这个非常规临界点的最有利参数区域。我们还发现了在n = 0/1轨道能级交叉附近存在一个新的各向异性无隙相的证据。
