# Calendar

One interesting question in interacting topological phases is how to characterize and reveal new topological properties in many-body states arising from interactions. In the search for a full answer, in this talk, I will introduce the monopole harmonic ordering in many-body topological states. This new class of three-dimensional topological many-body ordering states is characterized by a generalized Berry phase and monopole harmonic symmetries. Examples of monopole harmonic superconductivity and monopole harmonic density-wave states as well as their potentially realizations in doped Weyl semimetals will be discussed. The particle-particle (Cooper) pairing, or, the particle-hole pairing in these monopole harmonic ordering states inherit non-trivial Berry phases from Fermi surface topology. Their gap functions cannot be globally well-defined in momentum space, and hence go beyond standard symmetry classes based on spherical harmonics. Consequently, they exhibit topologically protected nodal structures regardless of specific ordering mechanism.

\n\nSPEAKER:Yi Li, John Hopkins University

190 ESB

false## Institute for Condensed Matter Theory Seminar: "Monopole Harmonic Ordering"

Speaker |
(sign-up)
Yi Li, John Hopkins University |
---|---|

Date: | 2/11/2019 |

Time: | 12 p.m. |

Location: | 190 ESB |

Sponsor: | Physics Department |

Event Type: | Seminar/Symposium |

One interesting question in interacting topological phases is how to characterize and reveal new topological properties in many-body states arising from interactions. In the search for a full answer, in this talk, I will introduce the monopole harmonic ordering in many-body topological states. This new class of three-dimensional topological many-body ordering states is characterized by a generalized Berry phase and monopole harmonic symmetries. Examples of monopole harmonic superconductivity and monopole harmonic density-wave states as well as their potentially realizations in doped Weyl semimetals will be discussed. The particle-particle (Cooper) pairing, or, the particle-hole pairing in these monopole harmonic ordering states inherit non-trivial Berry phases from Fermi surface topology. Their gap functions cannot be globally well-defined in momentum space, and hence go beyond standard symmetry classes based on spherical harmonics. Consequently, they exhibit topologically protected nodal structures regardless of specific ordering mechanism. |

To request disability-related accommodations for this event, please contact the person listed above, or the unit hosting the event.

## Event Mailing List

Receive Illinois Physics events weekly in your inbox.