Universal quantized thermal conductance in graphene
Universal quantized thermal conductance in graphene
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DOI：
10.1126/sciadv.aaw5798
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发表时间：
2019-07-01
期刊：
影响因子：
13.6
通讯作者：
Das, Anindya
中科院分区：
文献类型：
--
作者：
Srivastav, Saurabh Kumar;Sahu, Manas Ranjan;Das, Anindya
热导的普遍量子化提供了关于一个状态的拓扑序的信息。最近的测量表明，5/2态的热导观测值与Pfaftian或反Pfaftian模型都不一致，这引发了几篇理论文章。由于边缘重建产生的反向传播边缘通道的存在，使得分析变得复杂，这是将掺杂层与GaAs量子阱分离的必然结果，以及由此产生的软限制势。在这里，我们用敏感的噪声测温法测量了由SiO_2/Si或石墨后栅选通的六方氮化硼封装的石墨烯器件中具有原子尖端限制势的石墨烯的热导。对于nu=1、4/3、2和6的高原，热导的量子化精度在5%以内，强调了信息流的普遍性。这些石墨烯量子霍尔热输运测量将使人们能够对奇异系统有新的了解，比如石墨烯中的偶分母量子霍尔分数。
The universal quantization of thermal conductance provides information on a state's topological order. Recent measurements revealed that the observed value of thermal conductance of the 5/2 state is inconsistent with either Pfaftian or anti-Pfaftian model, motivating several theoretical articles. Analysis has been made complicated by the presence of counter-propagating edge channels arising from edge reconstruction, an inevitable consequence of separating the dopant layer from the GaAs quantum well and the resulting soft confining potential. Here, we measured thermal conductance in graphene with atomically sharp confining potential by using sensitive noise thermometry on hexagonal boron-nitride encapsulated graphene devices, gated by either SiO2/Si or graphite back gate. We find the quantization of thermal conductance within 5% accuracy for nu =1;4/3;2 and 6 plateaus, emphasizing the universality of flow of information. These graphene quantum Hall thermal transport measurements will allow new insight into exotic systems like even-denominator quantum Hall fractions in graphene.