Correlated Systems with Multicomponent Local Hilbert Spaces

Coordinators: George Jackeli, Natasha Perkins, Lucile Savary, and Oskar Vafek

KITP and the program coordinators will be delivering remote talk sessions to this program's participants. 

Theorists often idealize descriptions of solids via simple models, e.g. Ising or Hubbard, with a very small local Hilbert space. Typically, magnetic models involve s=1/2 spins on a lattice, and conductors are usually modeled by one or two bands. Similarly, many systems exist where magnetic and fermionic degrees of freedom are coupled, e.g. Kondo systems and itinerant magnets, but the minimal physics is usually simple, and the models are often considered in extreme limits. What happens when the local Hilbert space is larger and one must consider multiple entangled degrees of freedom? The focus of attention of the condensed matter community has gradually been shifting towards physical systems where the latter appears to be true. While some of these systems have been known for decades, a number of experimental and theoretical discoveries of strongly correlated phenomena have caused a notable revival of interest in the field. For example, the interplay of magnetism and topological band structures, and twisted bilayer graphene have proven to be very fertile areas.

This program will address the following questions: What entangled phases can one generate out of spin-orbital models? Are the natural/physical interactions different in band touching systems? What phases can result from the coupling of two strongly interacting systems, magnetic and conducting? How much of this physics exists in magic-angle twisted bilayer graphene and other moiré systems? Can such systems realize models akin to the SYK model which itself involves the coupling of N orbitals? What are the prospects for studying these systems with numerics?

Upcoming Speakers 

Sep 29  - Jason Alicea, Jennifer Cano

Oct 1  - Tarun Grover, Alexander Altland

Oct 6 - Emilia Morosan, Arun Paramekanti

Oct 8 - Joe Checkelsky, Maia Vergniori

Oct 13 - Catherine Pépin, Andrey Chubukov

Oct 15 - Subir Sachdev, Yuxuan Wang

Oct 20 - Amalia Coldea, Rafael Fernandes

Oct 22 - Dmitrii Maslov, James Analytis

Oct 27 - Kate Ross, Steve White

Oct 29 - Radu Coldea, Oleg Starykh

Nov 3 - Andrey Zheludev, Didier Poiblanc

Nov 5 - Collin Broholm, Federico Becca

Nov 10 - Hae-Young Kee, Roser Valentí

Nov 12 - Hide Takagi, Johannes Knolle

Nov 17 - Judit Romhanyi, Krzysztof Wohlfeld

Nov 19 - SungBin Lee, Ciaran Hickey

Nov. 23 - Masaki Oshikawa

Nov 24 - Kim BJ, Anna Keselman

Nov 26 - Thanksgiving

Dec 1 - Allan MacDonald, Pablo Jarillo-Herero

Dec 3 - Eva Andrey, Andrei Bernevig

Dec 8 - David Goldhaber-Gordon, Jian Kang

Dec 10 - Andrea Young, Leon Balents

Dec15 - Cory Dean, Ashvin Vishwanath

Dec 17 - Liang Fu, Marcel Franz