E-Mail IMAGE: X-ray diffraction intensities recorded in the vicinity of the (620,000) main reflection of the charge-density-wave (CDW) phase of the topological Weyl semimetal (TaSe4)2I. Small (red) indices label satellite reflections. The... view more Credit: MPI of Microstructure Physics Topological materials are characterised by unique electronic and physical properties that are determined by the underlying topology of their electronic systems. Scientists from the Max Planck Institutes for Microstructure Physics (Halle) and for Chemical Physics of Solids (Dresden) have now discovered that (TaSe4)2I is the first material in which a charge density wave induces a phase transition between the semimetal to insulator state.