Philippe Lecheminant

Criticality in self-dual sine-Gordon models

Abstract We discuss the nature of criticality in the β2=2πN self-dual extension of the sine-Gordon model. This field theory is related to the two-dimensional classical XY model with a N-fold degenerate symmetry-breaking field. We briefly overview the already studied cases N=2,4 and analyze in detail the case N=3 where a single phase transition in the three-state Potts universality class is expected to occur. The Z3 infrared critical properties of the β2=6π self-dual sine-Gordon model are derived using two non-perturbative approaches. On one hand, we map the model onto an integrable deformation of the Z4 parafermion theory. The latter is known to flow to a massless Z3 infrared fixed point. Another route is based on the connection with a chirally asymmetric, su(2)4⊗su(2)1 Wess–Zumino–Novikov–Witten model with anisotropic current–current interaction, where we explore the existence of a decoupling (Toulouse) point.

Symmetry-protected topological phases of alkaline-earth cold fermionic atoms in one dimension

We investigate the existence of symmetry-protected topological phases in one-dimensional alkaline-earth cold fermionic atoms with general half-integer nuclear spin I at halffilling. In this respect, some orbital degrees of freedom are required. They can be introduced by considering either the metastable excited state of alkaline-earth atoms or the p-band of the optical lattice. Using complementary techniques, we show that SU(2) Haldane topological phases are stabilised from these orbital degrees of freedom. On top of these phases, we find the emergence of topological phases with enlarged SU(2I?+?1) symmetry which depend only on the nuclear-spin degrees of freedom. The main physical properties of the latter phases are further studied using a matrix-product state approach. On the one hand, we find that these phases are symmetry-protected topological phases, with respect to inversion symmetry, when which is directly relevant to ytterbium and strontium cold fermions. On the other hand, for the other values of I(=half-odd integer), these topological phases are stabilised only in the presence of exact SU(2I?+?1) symmetry.

Molecular superfluid phase in systems of one-dimensional multicomponent fermionic cold atoms

We study a simple model of

Metal-insulator transition in the one-dimensional SU ( N ) Hubbard model

N

Effect of symmetry-breaking perturbations in the one-dimensionalSU(4)spin-orbital model

-component fermions with contact interactions which describes fermionic atoms with

Spin 3/2 fermions with attractive interactions in a one- dimensional optical lattice: phase diagrams, entanglement entropy, and the effect of the trap

N=2F+1

Spontaneous Plaquette Formation in the SU(4) Spin-Orbital Ladder

hyperfine states loaded into a one-dimensional optical lattice. We show by means of analytical and numerical approaches that, for attractive interaction, a quasi-long-range molecular superfluid phase emerges at low density. In such a phase, the pairing instability is strongly suppressed and the leading instability is formed from bound states made of

Phase transitions in the one-dimensional spin- S J 1 − J 2 XY model

N

The massive CP N −1 model for frustrated spin systems

fermions. At small density, the molecular superfluid phase is generic and exists for a wide range of attractive contact interactions without an

Confinement versus deconfinement of Cooper Pairs in One-Dimensional Spin-3/2 Fermionic Cold Atoms

\mathrm{SU}(N)