In the past few years, the theory of topological band structures has been generalized beyond topological insulators to include topological semimetals, including Weyl semimetals, Dirac semimetals and other “symmetry protected” topological states.  HgTe is a semimetal in which the degeneracy of the conduction and valence band at the G point is protected by symmetry.  In their early work on topological insulators, Fu and Kane showed that straining HgTe opens a gap at G, resulting in a topological insulator. 

Novel, cylindrical, ribbon-like membranes are formed when colloidal particles adsorb at the air-water interfaces of droplets confined between two glass plates (Fig. a). We have found that the ease with which such ribbon membranes bend depends on particle shape. Ellipsoidal particles on the interface locally deform the interface and thereby introduce strong capillary forces into the membrane that couple the particles into networks. The resultant membrane scaffolding can resist bending by as much as

Filaments in the cytoplasm that constitute a three dimensional cytoskeleton are formed by polymerization of the protein actin, which is initiated at distinct sites near the cell membrane.   Negatively charged lipids in

The Nebraska MRSEC Professor/Student Pairs Program brings in a professor and a student from non-research intensive four-year institutions to conduct research with Nebraska MRSEC scientists. The goal is to offer a research experience which benefits both the participants and the MRSEC projects.

Ferroelectrics comprise an important group of materials, which are characterized by a permanent electric polarization. This polarization can be switched which provides a possibility of using ferroelectrics in data storage and memory devices. Typically, polarization is switched by the application of the external electric field. Nebraska MRSEC researchers have shown that polarization can be switched by purely mechanical means: simply by pushing the tip of a scanning probe microscope against the ferroelectric

Using the expertise in nanoparticle synthesis and assembly built up in IRG 3, a MRSEC team comprised of members of the Jaeger and Talapin groups collaborated with Xiao-Min Lin and Jeffrey Guest at Argonne’s Center for Nanoscale Materials and John Sader from the University of Melbourne to develop the first completely self-assembled nano-mechanical resonator. It forms when a  nanoparticle monolayer drapes itself over a hole several microns in diameter to produce a 10nm thin, freestanding membrane that vibrates in the MHz range (transmission electron microscope images shown in left inset).

Discovery: A class of 2D covalent organic framework made of triphenyl- metal compounds are found to be topological insulators exhibiting robust nontrivial topological edge states. Approach: Predictive First-principles band structure and band topology calculations.