Reversal of quantized Hall drifts at noninteracting and interacting topological boundaries

• 成果类型: Article
• 署名作者: Zhu, Zijie; Gachter, Marius; Walter, Anne-Sophie; Viebahn, Konrad; Esslinger, Tilman
• 署名单位: Swiss Federal Institutes of Technology Domain; ETH Zurich
• 刊物名称: SCIENCE
• ISSN/ISSBN: 0036-11834
• DOI: 10.1126/science.adg3848
• 发表日期: 2024-04-19
• 页码: 317-320
• 关键词: edge states

摘要

The transport properties of gapless edge modes at boundaries between topologically distinct domains are of fundamental and technological importance. We experimentally studied long-distance quantized Hall drifts in a harmonically confined topological pump of ultracold fermionic atoms. We found that quantized drifts halt and reverse their direction when the atoms reach a critical slope of the confining potential, revealing the presence of a topological boundary. The drift reversal corresponded to a band transfer between a band with Chern number C = +1 and another with C = -1 through a gapless edge mode, in agreement with the bulk-edge correspondence for noninteracting particles. Nonzero repulsive Hubbard interactions led to the emergence of an additional edge in the system through a mechanism in which pairs of fermions are split.