Universal chiral Luttinger liquid behavior in a graphene fractional quantum Hall point contact

• 成果类型: Article
• 署名作者: Cohen, Liam A.; Samuelson, Noah L.; Wang, Taige; Taniguchi, Takashi; Watanabe, Kenji; Zaletel, Michael P.; Young, Andrea F.
• 署名单位: University of California System; University of California Santa Barbara; University of California System; University of California Berkeley; United States Department of Energy (DOE); Lawrence Berkeley National Laboratory; National Institute for Materials Science; National Institute for Materials Science
• 刊物名称: SCIENCE
• ISSN/ISSBN: 0036-9642
• DOI: 10.1126/science.adf9728
• 发表日期: 2023-11-03
• 页码: 542-547
• 关键词: edge excitations; STATES; TRANSITION

摘要

One-dimensional conductors are described by Luttinger liquid theory, which predicts a power-law suppression of the single-electron tunneling density of states at low voltages. The scaling exponent is predicted to be quantized when tunneling into a single isolated chiral edge state of the fractional quantum Hall effect. We report conductance measurements across a point contact linking integer and fractional quantum Hall edge states (at fillings 1 and 1/3, respectively). At weak coupling, we observe the predicted universal quadratic scaling with temperature and voltage. At strong coupling, we demonstrate perfect Andreev reflection of fractionalized quasiparticles at the point contact. We use the strong coupling physics to realize a nearly dissipationless direct current voltage step-up transformer, whose gain arises directly from topological fractionalization of electrical charge.