![\"Figure](\"https:\/\/www.newsbeep.com\/ca\/wp-content\/uploads\/2025\/08\/e99_1.png\")
<\/a><\/p>\nG. M. Ferguson et al. [1<\/a>]<\/p>\n \u00d7<\/a><\/p>\n Magnetic topological insulators (MTIs) are predicted to conduct electricity along their surfaces but act as insulators in their interior, a promising property for next-generation computing platforms. At low temperatures, MTIs can host the quantum anomalous Hall effect (QAHE). Discovered in 2013, the QAHE manifests as a quantized transverse conductivity when a current flows through a ferromagnetic slab without an external magnetic field. Now George Ferguson and Katja Nowack of Cornell University and their colleagues have observed that, contrary to expectations, edge currents in an MTI slab are present even after its quantized conductivity breaks down [1<\/a>]. MTIs attract interest in part because their surface currents are expected to flow without dissipation, a boon for energy-efficient devices.<\/p>\n In 2023, members of the research team observed that, under a low bias current that sustained the QAHE, bulk rather than edge currents dominated electronic transport in an MTI [2<\/a>]. The result was surprising because the currents that generate the QAHE are often assumed to be confined to the sample edges. In the new experiment, the team used scanning superconducting quantum interference device microscopy to measure the current distribution in the same MTI samples but with a larger bias current that quashed the QAHE. In contrast to the previous experiment, the team observed current concentrated near the sample\u2019s edges, which coexisted with a larger current distributed uniformly across the device width.<\/p>\n The team\u2019s models suggest that the observed edge currents arose from changes in magnetization brought on by gradients in electrostatic and chemical potential. The researchers say that the work will guide future studies geared toward clarifying the connection between topologically protected surface states and other electronic phenomena in MTIs.<\/p>\n \u2013Rachel Berkowitz<\/p>\n Rachel Berkowitz is a Corresponding Editor for\u00a0Physics Magazine<\/a> based in Vancouver, Canada.<\/p>\n ReferencesG. M. Ferguson et al., \u201cLocal potential distribution generates edge currents in a magnetic topological insulator,\u201d Phys. Rev. B 112, 075414 (2025)<\/a>.G. M. Ferguson et al., \u201cDirect visualization of electronic transport in a quantum anomalous Hall insulator,\u201d Nat. Mater. 22 (2023)<\/a>.Subject AreasRelated Articles
\nG. M. Ferguson et al. [1<\/a>]<\/p>\n<\/a><\/a><\/a> More Articles<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"August 13, 2025• Physics 18, s99 Edge currents are observed in a magnetic topological insulator even when conventional…\n","protected":false},"author":2,"featured_media":69747,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[24],"tags":[49,48,314,66],"class_list":{"0":"post-69746","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","7":"category-physics","8":"tag-ca","9":"tag-canada","10":"tag-physics","11":"tag-science"},"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/posts\/69746","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/comments?post=69746"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/posts\/69746\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/media\/69747"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/media?parent=69746"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/categories?post=69746"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/tags?post=69746"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}