Quantum Hall Thermal Conductance of an Isolated Edge Channel
by Dr. Bivas Dutta (Department of Condensed Matter Physics, Weizmann Institute of Science, Israel)
Tuesday, September 13, 2022 from to (Asia/Kolkata)
The quantum Hall effect (QHE) states, one of the earliest known examples of a topological insulator, are predicted to host exotic quasiparticles that make them one of the most sought after for application in topological quantum computations. A proposed host of such quasiparticles is the =5/2 QHE state. Gapless edge modes are ideal candidates for braiding experiments, which can reveal the state’s robustness to decoherence. Since the =5/2 state hosts a variety of edge modes (integer, fractional, neutral), a robust technique is needed to isolate the exotic modes while assuring that their original character remains intact. In this talk, I will present our recent work, where we exploited a novel technique to gap-out the integer modes of the =5/2 state by interfacing it with the integer state =2 and =3  , and measured the thermal conductance of the isolated =1/2 mode. Observing a thermal conductance of (with = 2 k B 2 /3h, the quantum of thermal conductance), assures the non-abelian nature of the =1/2 mode and its topological order  . Our result opens a new avenue to manipulate and test other QHE states and braid via interference of the isolated exotic modes. References: 1. Dutta, B., et al., Distinguishing between non-abelian topological orders in a quantum Hall system. Science, 2022. 375(6577): p. 193-197. 2. Dutta, B., et al., Isolated Ballistic Non-Abelian Interface Channel. Accepted in Science (2022), arXiv preprint arXiv:2109.11205, 2021.