The two-dimensional (2D) topological insulators (TI) realized in inverted semiconductor quantum wells exhibit unusual electric-transport properties [1] that have attracted great interest [2]. TI behavior is also found in other 2D and bulk materials [2,3]. The potential for interesting interplays between a TI's electronic and magnetic degrees of freedom has motivated our detailed theoretical study of electronic compressibility [4] and spin response [5] for electrons in the mercury-telluride-based 2D TI. Our work reveals unconventional properties that distinguish this paradigmatic TI material from all other currently known 2D electronic systems. We thus provide alternative means for experimental identification of the topological regime and extend current knowledge about the fundamentals of many-particle collective behaviour in solids.

References:
[1] M. Konig et al., Science 318, 766 (2007); A. Roth et al., Science 325, 294 (2009); C. Brune et al., Nat. Phys. 8, 485 (2012).
[2] X. Qi and S. Zhang, Rev. Mod. Phys. 83, 1057 (2011).
[3] M. Z. Hasan and J. E. Moore, Annu. Rev. Condens. Matter Phys. 2, 55 (2011).
[4] T. Kernreiter, M. Governale, and U. Zuelicke, Phys. Rev. B 93, 241304(R) (2016).
[5] T. Kernreiter, M. Governale, U. Zuelicke, and E. M. Hankiewicz, Phys. Rev. X 6, 021010 (2016).

After obtaining his Ph.D. from Indiana University, USA, in 1998, Ulrich Zuelicke undertook postdoctoral research at the University of Karlsruhe in Germany and has held permanent academic positions at Massey University (Palmerston North, New Zealand) from 2003 until his move to Victoria University of Wellington where he has been a Professor of Physics since 2011. Ulrich is a condensed-matter theorist interested in the study of unconventional materials realized in solid-state and ultra-cold-atom systems.