Quantum Topological Switches

Our new paper titled "Quantum topological switch and controllable quasi 1D wires in antimonene" is up on arXiv, and here is a brief summary of the big idea proposed there.

In our previous papers we showed that a 2-dimensional sheet of symmetry orbitals arranged in honeycomb lattice has very interesting effects, one of which is that the system is in a state of weak Topological Crystalline Insulator. The protection of this weak surface state is through the presence of inversion symmetry in the 2D system.

Because of the buckled nature of the system, we show that applying a simple electric field perpendicular to the system (just like in case of gating) can break this inversion and thus gaps the surface state. A second device uses almost the same principle, but instead applies electric field locally breaking the inversion at different regions, which we showed creates 1D channel pathways inside the system. This can in principle be used to design pixelated patches for configurable circuits that have unique 1D semi-conducting wires.

Secondly, we showed that this system is a Higher Order Topological Insulator (HOTI), again protected by inversion symmetry. Breaking the symmetry forces the symmetry into . This forces the anomalous fractional charge excitations in (which exist in 6 corners) to disappear and concentrate in symmetric fashion (3 corners).

The paper can be found on arXiv:2005.06096.