Braun Center for Submicron Research, Department of Condensed Matter Physics, Weizmann Institute of Science, Rehovot 76100, Israel.
Phys Rev Lett. 2018 Jul 13;121(2):026801. doi: 10.1103/PhysRevLett.121.026801.
The thermal Hall conductance in the half-filled first Landau level was recently measured to take the quantized noninteger value κ_{xy}=5/2 (in units of temperature times π^{2}k_{B}^{2}/3h), which indicates a non-Abelian phase of matter. Such exotic states have long been predicted to arise at this filling factor, but the measured value disagrees with numerical studies, which predict κ_{xy}=3/2 or 7/2. We resolve this contradiction by invoking the disorder-induced formation of mesoscopic puddles with locally κ_{xy}=3/2 or 7/2. Interactions between these puddles generate a coherent macroscopic state that exhibits a plateau with quantized κ_{xy}=5/2. The non-Abelian quasiparticles characterizing this phase are distinct from those of the microscopic puddles and, by the same mechanism, could even emerge from a system comprised of microscopic Abelian puddles.
最近测量到半满第一朗道能级的热霍尔电导取量子非整数值 κ_{xy}=5/2（温度乘以 π^{2}k_{B}^{2}/3h 的单位），这表明物质具有非阿贝尔相。在这个填充因子下，长期以来一直预测会出现这种奇异状态，但测量值与数值研究不一致，数值研究预测 κ_{xy}=3/2 或 7/2。我们通过调用由无序诱导的具有局部 κ_{xy}=3/2 或 7/2 的介观液滴的形成来解决这个矛盾。这些液滴之间的相互作用产生了一个相干的宏观状态，表现出具有量子化 κ_{xy}=5/2 的平台。表征这个相的非阿贝尔准粒子与微观液滴中的准粒子不同，并且通过相同的机制，即使是由微观阿贝尔液滴组成的系统也可能出现这种准粒子。
