## molecule-type workshop

The international molecule-type workshop program is intended for intensive discussions and collaborations among participants for an extended period of time, from two weeks to a few months. Provided that a proposal satisfies a few requirements, the format of the workshop is rather flexible. For example, the style of a workshop, including whether it is closed or open to the public, is totally up to the organizers; it may be a brain-storming kind of workshop on some new topic, or it may be for specific collaborations/projects, or else. YITP hopes that through these workshops the participants will feel at home, have valuable discussions, and may be able to contribute to further progress in theoretical physics.

## "Exotic States of Matter with SU(N) Symmetry"

In condensed-matter physics, systems invariant under high symmetries like SU(N) have been thought of, for a long time, as rather idealized and used mainly for mathematical convenience. The situation dramatically changed when alkaline-earth fermionic atoms and their cousins (e.g., $$^{87}$$Sr, $$^{171}$$Yb, and $$^{173}$$Yb) were cooled down to quantum degeneracy in the middle of 2000s. The hallmark of these systems of ultra-cold atoms is that the absence of the hyperfine coupling between nuclear spins and electron angular momenta leads to (almost) perfect SU(N) symmetry without any fine tuning. The possibility of realizing SU(N) symmetry in realistic settings sparked extensive research both in theory and in experiments, and now it is realized that the study of SU(N)-invariant systems is not just a trivial generalization from N=2 to arbitrary N but bears very rich physics ranging from exotic (topological) states of matter to quantum simulations of, e.g., non-Abelian lattice gauge theories in laboratories. The goal of this two-week workshop is to discuss about the latest issues in this rapidly developing field and start new collaborations among the participants. The rough format of this molecule-type workshop is as follows. To have ample time for discussions and collaborations, we have one-two talks (one in the morning and one in the afternoon) a day that help to share the knowledge about what the project members are interested in as well as a few review talks/short lectures by theorists and experimentalists. We divide the whole period into the first week that mainly covers problems in one-dimensional systems and the second dealing with those in two and three-dimensional systems. The topics covered include: SU(N) quantum spin chains (exact solutions, field theories, etc.), SU(N)-symmetric electron systems [SU(N) Hubbard, SU(N) Kondo, etc.], exotic quantum states in SU(N) spin systems (symmetry-protected topological phases, chiral spin liquids, etc.), and numerical methods (DMRG/MPS, PEPS, etc.) for SU(N)-invariant systems.

The molecular-type workshop "Exotic States of Matter with SU(N) Symmetry" is sponsored by Yukawa International Program for Quark-Hadron Sciences (YIPQS). [Here is the list of conferences/workshops supported by the program (since 2007)].

## topics

The international molecular workshop "Exotic States of Matter with SU(N) Symmetry" will mainly cover the following topics:

(a). Fermion systems:
SU(N) Hubbard models, SU(N) Kondo systems, Mott-insulating and superfluid phases, etc.
(b). SU(N) "spin" systems:
Quantum spin liquids, Novel ordered states, Symmetry-protected topological order, etc.
(c). Various methods:
Field-theoretical approaches (CFT, etc.), Exact (Bethe ansatz) solutions, Numerical methods (DMRG, tensor network, quantum Monte-Carlo, etc.)
(d). Other related topics

We will also incorporate some informal talks on preliminary results or newly developing fields.

Tentative schedule is as follows:

(A) July 4-8:
Topics in one dimension and related problems
(B) July 11-15:
Problems in two (and three) dimensional systems and other topics

## venue

The workshops will be held at:

Yukawa Institute for Theoretical Physics (YITP)
Kyoto University, Kyoto 606-8502, Japan
Phone: +81-75-753-7008
Fax: +81-75-753-7010

YITP is located in "North Campus" of Kyoto University (building No.12 in Campus Map). See also "information" for the access.
For more details about YITP, visit YITP homepage.

## organizers

Sylvain Capponi (Toulouse)

Philippe Lecheminant (Cergy-Pontoise)

Frederic Mila (EPFL)

Keisuke Totsuka (YITP, Kyoto)