Topological kink plasmons on magnetic-domain boundaries
- Univ. of California, Berkeley, CA (United States); Argonne National Lab. (ANL), Argonne, IL (United States)
- Univ. of California, Berkeley, CA (United States)
- Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)
- Florida State Univ., Tallahassee, FL (United States). National High Magnetic Field Lab. (MagLab)
- Purdue Univ., West Lafayette, IN (United States)
- Argonne National Lab. (ANL), Argonne, IL (United States)
- Univ. of California, Berkeley, CA (United States); Univ. of Hong Kong (China)
Two-dimensional topological materials bearing time reversal-breaking magnetic fields support protected one-way edge modes. Normally, these edge modes adhere to physical edges where material properties change abruptly. However, even in homogeneous materials, topology still permits a unique form of edge modes - kink modes - residing at the domain boundaries of magnetic fields within the materials. This scenario, despite being predicted in theory, has rarely been demonstrated experimentally. Here, we report our observation of topologically-protected high-frequency kink modes - kink magnetoplasmons (KMPs) - in a GaAs/AlGaAs two-dimensional electron gas (2DEG) system. These KMPs arise at a domain boundary projected from an externally-patterned magnetic field onto a uniform 2DEG. They propagate unidirectionally along the boundary, protected by a difference of gap Chern numbers (+/- 1) in the two domains. They exhibit large tunability under an applied magnetic field or gate voltage, and clear signatures of nonreciprocity even under weak-coupling to evanescent photons.
- Research Organization:
- Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States); Argonne National Laboratory (ANL), Argonne, IL (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC); Danish Council for Independent Research; US Air Force Office of Scientific Research (AFOSR); National Science Foundation (NSF)
- Grant/Contract Number:
- AC02-05CH11231; AC02-06CH11357; FG02-05ER46212; SC0006671; FA9550-12-1-0488; OSR-2016-CRG5-2950-03; DFF-6108-00667; DMR-0654118
- OSTI ID:
- 1591818
- Alternate ID(s):
- OSTI ID: 1604994
- Journal Information:
- Nature Communications, Vol. 10, Issue 1; ISSN 2041-1723
- Publisher:
- Nature Publishing GroupCopyright Statement
- Country of Publication:
- United States
- Language:
- English
Web of Science
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