التفاصيل البيبلوغرافية
| العنوان: |
Observation of ballistic upstream modes at fractional quantum Hall edges of graphene |
| المؤلفون: |
Kumar, Ravi, Srivastav, Saurabh Kumar, Spånslätt, Christian, Watanabe, K., Taniguchi, T., Gefen, Yuval, Mirlin, Alexander D., Das, Anindya |
| المصدر: |
Nature Communications volume 13, Article number: 213 (2022) |
| سنة النشر: |
2021 |
| المجموعة: |
Condensed Matter |
| مصطلحات موضوعية: |
Condensed Matter - Mesoscale and Nanoscale Physics |
| الوصف: |
The structure of edge modes at the boundary of quantum Hall (QH) phases forms the basis for understanding low energy transport properties. In particular, the presence of ``upstream'' modes, moving against the direction of charge current flow, is critical for the emergence of renormalized modes with exotic quantum statistics. Detection of excess noise at the edge is a smoking gun for the presence of upstream modes. Here we report on noise measurements at the edges of fractional QH (FQH) phases realized in dual graphite-gated bilayer graphene devices. A noiseless dc current is injected at one of the edge contacts, and the noise generated at contacts at $L= 4\,\mu$m or $10\,\mu$m away along the upstream direction is studied. For integer and particle-like FQH states, no detectable noise is measured. By contrast, for ``hole-conjugate'' FQH states, we detect a strong noise proportional to the injected current, unambiguously proving the existence of upstream modes. The noise magnitude remaining independent of length together with a remarkable agreement with our theoretical analysis demonstrates the ballistic nature of upstream energy transport, quite distinct from the diffusive propagation reported earlier in GaAs-based systems. Our investigation opens the door to the study of upstream transport in more complex geometries and in edges of non-Abelian phases in graphene. |
| نوع الوثيقة: |
Working Paper |
| DOI: |
10.1038/s41467-021-27805-4 |
| URL الوصول: |
http://arxiv.org/abs/2107.12616 |
| رقم الانضمام: |
edsarx.2107.12616 |
| قاعدة البيانات: |
arXiv |