Department of Physics, University of California, Riverside, Riverside, California 92521, USA.
Phys Rev Lett. 2010 Dec 10;105(24):246601. doi: 10.1103/PhysRevLett.105.246601. Epub 2010 Dec 6.
We report pronounced magnetoconductance oscillations observed on suspended bilayer and trilayer graphene devices with mobilities up to 270,000 cm²/V s. For bilayer devices, we observe conductance minima at all integer filling factors ν between 0 and -8, as well as a small plateau at ν=1/3. For trilayer devices, we observe features at ν=-1, -2, -3, and -4, and at ν∼0.5 that persist to 4.5 K at B=8 T. All of these features persist for all accessible values of Vg and B, and could suggest the onset of symmetry breaking of the first few Landau levels and fractional quantum Hall states.
我们报告了在悬浮双层和三层石墨烯器件中观察到的明显磁导率振荡，这些器件的迁移率高达 270000 cm²/V s。对于双层器件，我们在 0 到-8 的所有整数填充因子 ν 处观察到电导极小值，以及 ν=1/3 处的一个小平台。对于三层器件，我们在 ν=-1、-2、-3 和-4 处以及 ν∼0.5 处观察到特征，在 B=8 T 时，这些特征一直持续到 4.5 K。所有这些特征在所有可访问的 Vg 和 B 值下都存在，这可能表明前几个朗道能级和分数量子霍尔态的对称性破缺开始出现。
