Topological change of topological materials

We have investigated structural and electrical properties of ribbon-knot crystals of low-dimensional conductors, such as TaSe3 (superconductor) and NbSe3 (charge-density-waves conductor), having some topological invariant characteristics. We cut some specimens of TaSe3 ring crystals using focused ion beam sputtering to obtain the structural property (e.g., elasticity and plasticity). The cut specimens of ring crystal transformed to arc-shape with homogeneous curvatures, and the cut thick rings had a tendency to keep strongly their shapes. From result of electrical measurement at low temperature, whisker and thin ring crystals of TaSe3 show superconductivity, however, thick rings show increase resistance with decreasing temperature. The geometrical parameter, thickness, dominates the structural and the electrical properties in the ring crystals.