Isolated Ballistic Non-Abelian Interface Channel

• Published in: arXiv.org
• Main Authors: Dutta, Bivas, Umansky, Vladimir, Banerjee, Mitali, Heiblum, Moty
• Format: Paper Journal Article
• Language: English
• Published: Ithaca Cornell University Library, arXiv.org 15.11.2021
• Subjects: Braiding; Elementary excitations; Fault tolerance; Integers; Interference; Measurement techniques; Physics - Mesoscale and Nanoscale Physics; Physics - Quantum Physics; Physics - Strongly Correlated Electrons; Quantum computing; Quantum Hall effect; Thermal conductivity; Topology
• ISSN: 2331-8422
• DOI: 10.48550/arxiv.2109.11205

Non-abelian anyons are prospective candidates for fault-tolerant topological quantum computation due to their long-range entanglement. Curiously these quasiparticles are charge-neutral, hence elusive to most conventional measurement techniques. A proposed host of such quasiparticles is the \(\nu\)=5/2 quantum Hall state. The gapless edge modes can provide the topological order of the state, which in turn identifies the chirality of the non-abelian mode. Since the \(\nu\)=5/2 state hosts a variety of edge modes (integer, fractional, neutral), a robust technique is needed to isolate the fractional channel while retaining its original non-abelian character. Moreover, a single non-abelian channel can be easily manipulated to interfere, thus revealing the state's immunity to decoherence. In this work, we exploit a novel approach to gap-out the integer modes of the \(\nu\)=5/2 state by interfacing the state with integer states, \(\nu\)=2 & \(\nu\)=3 (1). The electrical conductance of the isolated interface channel was 0.5e\(^2\)/h, as expected. More importantly, we find a thermal conductance of 0.5\(\kappa_0\)T (with \(\kappa_0\)=\(\pi^2k_B^2\)/3h), confirming unambiguously the non-abelian nature of the \(\nu\)=1/2 interface channel and its Particle-Hole Pfaffian topological order. Our result opens new avenues to manipulate and test other exotic QHE states and braid, via interference, the isolated fractional channels.