Srivastav Saurabh Kumar, Sahu Manas Ranjan, Watanabe K, Taniguchi T, Banerjee Sumilan, Das Anindya
Department of Physics, Indian Institute of Science, Bangalore 560012, India.
National Institute of Material Science, 1-1 Namiki, Tsukuba 305-0044, Japan.
Sci Adv. 2019 Jul 12;5(7):eaaw5798. doi: 10.1126/sciadv.aaw5798. eCollection 2019 Jul.
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 state is inconsistent with either Pfaffian or anti-Pfaffian 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 SiO/Si or graphite back gate. We find the quantization of thermal conductance within 5% accuracy for ν = 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.
热导率的普适量子化提供了有关一个态的拓扑序的信息。最近的测量结果表明,该态的热导率观测值与Pfaffian或反Pfaffian模型均不一致,这激发了几篇理论文章的出现。由于边缘重构产生的反向传播边缘通道的存在,分析变得复杂,而边缘重构是将掺杂层与GaAs量子阱分离以及由此产生的软限制势的必然结果。在这里,我们通过在由SiO/Si或石墨背栅门控的六方氮化硼封装的石墨烯器件上使用灵敏的噪声热测量法,测量了具有原子级尖锐限制势的石墨烯中的热导率。我们发现,对于ν = 以及6个平台,热导率的量子化精度在5%以内,强调了信息流的普适性。这些石墨烯量子霍尔热输运测量将为诸如石墨烯中偶数分母量子霍尔分数等奇异系统提供新的见解。