Phys.org  March 22, 2024 A boundary mode localized on one side of a finite-size lattice can tunnel to the opposite side which results in unwanted couplings and the tunneling probability decays exponentially with the size of the system which requires many lattice sites before eventually becoming negligibly small. An international team of researchers (USA – PNNL, China) showed that the tunneling probability for some boundary modes can apparently vanish at specific wavevectors and a boundary mode can be completely trapped within very few lattice sites where the bulk bandgap is not even well-defined. The number of trapped states equaled the […]