I will talk about a new type of critical quantum liquids, dubbed Stiefel liquids, that can emerge in quantum magnets. Our theory is based on 2+1 dimensional nonlinear sigma models on target space SO(N)/SO(4), supplemented with Wess-Zumino-Witten terms. We argue that the Stiefel liquids form a class of 3d CFTs with extraordinary properties, such as large emergent symmetries, a cascade structure, and nontrivial quantum anomalies. We show that the well known deconfined quantum critical point and U(1) Dirac spin liquid (i.e. Nf=4 QED3) are unified as two special examples of Stiefel liquids, with N=5 and N=6, respectively. Furthermore, we conjecture that Stiefel liquids with N>6 are non-Lagrangian, in the sense that under renormalization group they flow to infrared (conformally invariant) fixed points that cannot be described by any renormalizable continuum Lagrangian. I will also discuss a physical way to realize Stiefel liquids (both the Dirac spin liquid and N=7 non-Lagrangian Stiefel liquid) in quantum spin systems, for example, on triangular or kagome lattice, through the intertwinement of symmetry breaking orders.
Participer à la réunion Zoom
ID de réunion : 827 5770 2598
Code secret : 498440
IHES Covid-19 regulations:
- all the participants who will attend the event in person will have to keep their mask on in indoor spaces
and where the social distancing is not possible;
- speakers will be free to wear their mask or not at the moment of their talk if they feel more comfortable
- Up to 70 persons in the conference room, every participant will be asked to be able to provide a health pass
- Over 70 persons in the conference room, every participant will be asked to provide a health pass which will
be checked at the entrance of the conference room.
Pour être informé des prochains séminaires vous pouvez vous abonner à la liste de diffusion en écrivant un mail à firstname.lastname@example.org avec comme sujet: "subscribe quantum_encounters_seminar PRENOM NOM"
(indiquez vos propres prénom et nom) et laissez le corps du message vide.
Vasily Pestun & Slava Rychkov