Quantum Matter Seminar - Taylor Hughes (University of Illinois) "Higher Order Topological Phases: Quadrupoles, Meta-materials and Beyond"

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Taylor Hughes (University of Illinois) 12/3/18 Condensed Matter seminar speaker
December 3, 2018
11:30AM - 12:30PM
Location
1080 Physics Research Building - Smith Seminar Room

Date Range
Add to Calendar 2018-12-03 11:30:00 2018-12-03 12:30:00 Quantum Matter Seminar - Taylor Hughes (University of Illinois) "Higher Order Topological Phases: Quadrupoles, Meta-materials and Beyond"

In this talk we present a new class of phases of matter called higher-order topological phases. Such systems exhibit gapped boundaries that are themselves lower-dimensional topological phases. Furthermore, they manifest topologically protected states at intersections between multiple surfaces. These states can, e.g., carry fractional charge, or be chiral propagating modes. We show that some of the simplest examples of these phases are connected to materials with quantized electric quadrupole moments, and illustrate how they can be realized in a variety of meta-material systems. We will also review the first experimental evidence for these phases in meta-material contexts.  To characterize these new insulating phases of matter, we introduce a new type of invariant that had been previously overlooked, and we show how these invariants can predict a collection of new phenomena. 

 

1080 Physics Research Building - Smith Seminar Room Department of Physics physics@osu.edu America/New_York public
Description

In this talk we present a new class of phases of matter called higher-order topological phases. Such systems exhibit gapped boundaries that are themselves lower-dimensional topological phases. Furthermore, they manifest topologically protected states at intersections between multiple surfaces. These states can, e.g., carry fractional charge, or be chiral propagating modes. We show that some of the simplest examples of these phases are connected to materials with quantized electric quadrupole moments, and illustrate how they can be realized in a variety of meta-material systems. We will also review the first experimental evidence for these phases in meta-material contexts.  To characterize these new insulating phases of matter, we introduce a new type of invariant that had been previously overlooked, and we show how these invariants can predict a collection of new phenomena.