Abstract
A Chern insulator is a two-dimensional material that hosts chiral edge states produced by the combination of topology with time reversal symmetry breaking. Such edge states are perfect one-dimensional conductors, which may exist not only on sample edges, but on any boundary between two materials with distinct topological invariants (or Chern numbers). Engineering of such interfaces is highly desirable due to emerging opportunities of using topological edge states for energy-efficient information transmission. Here, we report a chiral edge-current divider based on Chern insulator junctions formed within the layered topological magnet MnBi2Te4. We find that in a device containing a boundary between regions of different thickness, topological domains with different Chern numbers can coexist. At the domain boundary, a Chern insulator junction forms, where we identify a chiral edge mode along the junction interface. We use this to construct topological circuits in which the chiral edge current can be split, rerouted, or switched off by controlling the Chern numbers of the individual domains. Our results demonstrate MnBi2Te4 as an emerging platform for topological circuits design.
| Original language | English |
|---|---|
| Article number | 5967 |
| Journal | Nature Communications |
| Volume | 13 |
| Issue number | 1 |
| DOIs | |
| State | Published - Dec 2022 |
Funding
Authors thank Xi Wang and Jonathan Kephart for advice on device fabrication. The chiral edge current divider efforts were mainly supported as part of Programmable Quantum Materials, an Energy Frontier Research Center funded by the U.S. Department of Energy (DOE), Office of Science, Basic Energy Sciences (BES), under award DE-SC0019443. The control of the Chern numbers was mainly supported by AFOSR FA9550-21-1-0177. The authors also acknowledge the use of the facilities and instrumentation supported by NSF MRSEC DMR-1719797. J.Y. acknowledges support from the U.S. Department of Energy, Office of Science, Basic Energy Sciences, Materials Sciences and Engineering Division. C.-Z.C. acknowledges the partial support from the Gordon and Betty Moore Foundation’s EPiQS Initiative (Grant GBMF9063). Y.-T.C. acknowledge support from NSF under award DMR-2004701, and the Hellman Fellowship award. X.X. and J.-H.C. acknowledge the support from the State of Washington funded Clean Energy Institute. Authors thank Xi Wang and Jonathan Kephart for advice on device fabrication. The chiral edge current divider efforts were mainly supported as part of Programmable Quantum Materials, an Energy Frontier Research Center funded by the U.S. Department of Energy (DOE), Office of Science, Basic Energy Sciences (BES), under award DE-SC0019443. The control of the Chern numbers was mainly supported by AFOSR FA9550-21-1-0177. The authors also acknowledge the use of the facilities and instrumentation supported by NSF MRSEC DMR-1719797. J.Y. acknowledges support from the U.S. Department of Energy, Office of Science, Basic Energy Sciences, Materials Sciences and Engineering Division. C.-Z.C. acknowledges the partial support from the Gordon and Betty Moore Foundation’s EPiQS Initiative (Grant GBMF9063). Y.-T.C. acknowledge support from NSF under award DMR-2004701, and the Hellman Fellowship award. X.X. and J.-H.C. acknowledge the support from the State of Washington funded Clean Energy Institute.
