Long-range nontopological edge currents in charge-neutral graphene
Van der Waals heterostructures display numerous unique electronic properties. Nonlocal measurements, wherein a voltage is measured at contacts placed far away from the expected classical flow of charge carriers, have been widely used in the search for novel transport mechanisms, including dissipatio...
| Main Authors: | , , , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Springer Science and Business Media LLC
2022
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| Online Access: | https://hdl.handle.net/1721.1/142067 |
| _version_ | 1826198637839908864 |
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| author | Aharon-Steinberg, A Marguerite, A Perello, DJ Bagani, K Holder, T Myasoedov, Y Levitov, LS Geim, AK Zeldov, E |
| author_facet | Aharon-Steinberg, A Marguerite, A Perello, DJ Bagani, K Holder, T Myasoedov, Y Levitov, LS Geim, AK Zeldov, E |
| author_sort | Aharon-Steinberg, A |
| collection | MIT |
| description | Van der Waals heterostructures display numerous unique electronic properties. Nonlocal measurements, wherein a voltage is measured at contacts placed far away from the expected classical flow of charge carriers, have been widely used in the search for novel transport mechanisms, including dissipationless spin and valley transport1-9, topological charge-neutral currents10-12, hydrodynamic flows13 and helical edge modes14-16. Monolayer1-5,10,15-19, bilayer9,11,14,20 and few-layer21 graphene, transition-metal dichalcogenides6,7 and moiré superlattices8,10,12 have been found to display pronounced nonlocal effects. However, the origin of these effects is hotly debated3,11,17,22-24. Graphene, in particular, exhibits giant nonlocality at charge neutrality1,15-19, a striking behaviour that has attracted competing explanations. Using a superconducting quantum interference device on a tip (SQUID-on-tip) for nanoscale thermal and scanning gate imaging25, here we demonstrate that the commonly occurring charge accumulation at graphene edges23,26-31 leads to giant nonlocality, producing narrow conductive channels that support long-range currents. Unexpectedly, although the edge conductance has little effect on the current flow in zero magnetic field, it leads to field-induced decoupling between edge and bulk transport at moderate fields. The resulting giant nonlocality at charge neutrality and away from it produces exotic flow patterns that are sensitive to edge disorder, in which charges can flow against the global electric field. The observed one-dimensional edge transport is generic and nontopological and is expected to support nonlocal transport in many electronic systems, offering insight into the numerous controversies and linking them to long-range guided electronic states at system edges. |
| first_indexed | 2024-09-23T11:07:53Z |
| format | Article |
| id | mit-1721.1/142067 |
| institution | Massachusetts Institute of Technology |
| language | English |
| last_indexed | 2024-09-23T11:07:53Z |
| publishDate | 2022 |
| publisher | Springer Science and Business Media LLC |
| record_format | dspace |
| spelling | mit-1721.1/1420672022-04-26T03:27:50Z Long-range nontopological edge currents in charge-neutral graphene Aharon-Steinberg, A Marguerite, A Perello, DJ Bagani, K Holder, T Myasoedov, Y Levitov, LS Geim, AK Zeldov, E Van der Waals heterostructures display numerous unique electronic properties. Nonlocal measurements, wherein a voltage is measured at contacts placed far away from the expected classical flow of charge carriers, have been widely used in the search for novel transport mechanisms, including dissipationless spin and valley transport1-9, topological charge-neutral currents10-12, hydrodynamic flows13 and helical edge modes14-16. Monolayer1-5,10,15-19, bilayer9,11,14,20 and few-layer21 graphene, transition-metal dichalcogenides6,7 and moiré superlattices8,10,12 have been found to display pronounced nonlocal effects. However, the origin of these effects is hotly debated3,11,17,22-24. Graphene, in particular, exhibits giant nonlocality at charge neutrality1,15-19, a striking behaviour that has attracted competing explanations. Using a superconducting quantum interference device on a tip (SQUID-on-tip) for nanoscale thermal and scanning gate imaging25, here we demonstrate that the commonly occurring charge accumulation at graphene edges23,26-31 leads to giant nonlocality, producing narrow conductive channels that support long-range currents. Unexpectedly, although the edge conductance has little effect on the current flow in zero magnetic field, it leads to field-induced decoupling between edge and bulk transport at moderate fields. The resulting giant nonlocality at charge neutrality and away from it produces exotic flow patterns that are sensitive to edge disorder, in which charges can flow against the global electric field. The observed one-dimensional edge transport is generic and nontopological and is expected to support nonlocal transport in many electronic systems, offering insight into the numerous controversies and linking them to long-range guided electronic states at system edges. 2022-04-25T18:37:59Z 2022-04-25T18:37:59Z 2021 2022-04-25T18:33:51Z Article http://purl.org/eprint/type/JournalArticle https://hdl.handle.net/1721.1/142067 Aharon-Steinberg, A, Marguerite, A, Perello, DJ, Bagani, K, Holder, T et al. 2021. "Long-range nontopological edge currents in charge-neutral graphene." Nature, 593 (7860). en 10.1038/S41586-021-03501-7 Nature Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. application/pdf Springer Science and Business Media LLC arXiv |
| spellingShingle | Aharon-Steinberg, A Marguerite, A Perello, DJ Bagani, K Holder, T Myasoedov, Y Levitov, LS Geim, AK Zeldov, E Long-range nontopological edge currents in charge-neutral graphene |
| title | Long-range nontopological edge currents in charge-neutral graphene |
| title_full | Long-range nontopological edge currents in charge-neutral graphene |
| title_fullStr | Long-range nontopological edge currents in charge-neutral graphene |
| title_full_unstemmed | Long-range nontopological edge currents in charge-neutral graphene |
| title_short | Long-range nontopological edge currents in charge-neutral graphene |
| title_sort | long range nontopological edge currents in charge neutral graphene |
| url | https://hdl.handle.net/1721.1/142067 |
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