Pressure-induced topological insulating behavior in the ternary chalcogenide Ge(2)Sb(2)Te(5)

• We unraveled the pressure-induced topological insulating behavior in Ge(2)Sb(2)Te(5) (GST) by means of ab initio calculations. We have shown that the spin-orbit interaction separates the twofold degenerate Ge p(x)p(y) Sb p(x)p(y) Te p(x)p(y) state to an upper and a lower level and enhances the energy level of Ge s Sb s Te p(z)/Ge p(z) Sb p(z) Te s states. Consequently, the sign of parity changes by inversing the characterizations of conduction band minimum and valence band maximum in a certain range of pressures. Moreover, the surface band structure with the Dirac cone feature was observed. The present results suggest that GST-relatedmaterials are a new family of pressure-induced topological insulators.

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NATURVETENSKAP  -- Fysik (hsv//swe)

NATURAL SCIENCES  -- Physical Sciences (hsv//eng)

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