A triumph of contemporary physics is the highly successful description of the most fundamental constituents of Nature and their excitations. Recent theories of “topological insulators” [1,2] have shown that in the complex and emergent world of condensed matter physics, one can engineer the interplay between fundamental symmetries, band structure and spin-orbit coupling to create novel energy-spin-momentum relationships for band electrons and to yield effective realizations of exotic particles predicted but yet unobserved in Nature.  This Colloquium will describe the experimental routes we are pursuing in this context to build "detectors" for such particles, by coupling the surface states of a topological insulator with the gauge symmetry breaking effects of superconductivity [3] and the time-reversal symmetry breaking effect of magnetism [4.5].
1. M. Z. Hasan and C. L. Kane, Rev. Mod. Phys. 82, 3045 (2010).
2. Xiao -Liang Qi and Shou-Cheng. Zhang, Rev. Mod. Phys. 83, 1057 (2011).
3. Duming Zhang et al., Phys. Rev. B 84, 165120 (2011).
4. Su-Yang Xu et al., Nature Physics 8, 616 (2012).
5. Duming Zhang et al., arxiv: 1206.2908.