Trimming edge-states of topological insulator: new class of material with unconventional two way edge transport

https://www.fleet.org.au/blog/topological-gardening-to-achieve-unexpected-spin-transport/

"topological crystalline insulator 1-way path conducts electricity without energy loss due to resistance... extracting edge spin current in 2D topological material, planar bismuthine... edge current suppressed when symmetry supporting nontrivial band topology broken... applying external electric fields and substrate potentials selectively adjust alignment between bulk and edge bands preserving bulk band topology... allow conducting edge channels even with large external electric field... low-energy-consuming electronics"