Layered BiSe in the trigonal $P\overline{3}m1$ phase is a weak topological insulator and candidate crystalline insulator. Here using structural, spectroscopic, resistance measurements at high pressure density functional theory calculations, we report that exhibits rich diagram with emergence of superconductivity above 7 GPa. Structural transitions into SnSe-type energetically tangled orthorhomb...

It has been remarked in several previous works that the combination of center vortices and nexuses (a nexus is a monopole-like soliton whose world line mediates certain allowed changes of field strengths on vortex surfaces) carry topological charge quantized in units of 1/N for gauge group SU(N). These fractional charges arise from the interpretation of the standard topological charge ∫ GG̃ as a...