RNA nanotechnology has the great potential to allow us to produce well-defined nanostructures and devices inside cells and thus open up a wide range of design opportunities in synthetic biology. To achieve this goal we need to understand the design principles of geometry, folding kinetics and topology that will allow us to genetically encode well-defined RNA nanostructures that self-assemble during the transcription process. We have recently introduced the single-stranded RNA origami method and validated the architecture by transcribing RNA tiles that assemble into lattices of different geometries. I will introduce new software tools that allow interactive design of RNA origami structures using a library of functional modules and new sequence design approaches that allow large structures to be designed. Also I will show our latest progress in developing larger three-dimensional RNA origami structures and functional RNA nanodevices with applications in biosensing and diagnostics.
Deconfined criticality is a concept that has emerged in recent years to describe quantum phase transitions beyond the Landau-Ginzburg paradigm. Its basic idea is that a continuous quantum phase transition between two different symmetry broken phases is generically possible, if it is driven by the proliferation of topological defects which carry quantum numbers related to the order parameter of the other phase. The prime example for a deconfined quantum critical point is the SU(2) Neel - valence bond solid (VBS) transition on the square lattice. In this talk I will describe a generalization to a deconfined quantum critical point in SU(3) antiferromagnets on the triangular lattice. Studying the critical theory from both sides by RG methods and analysis of the topological defects, one can provide strong evidence for a continuous phase transition, opposed to a naive Landau-Ginzburg expectation.