Properties of flux phases in the t-J model

Thomas Maurice Rice

Christine Cartwright, Gabriele De Chiara, Matteo Rizzi

We explore the effects of geometric frustration within a one-dimensional Bose-Hubbard model using a chain of rhombi subject to a magnetic flux. The competition of tunneling, self-interaction, and magnetic flux gives rise to the emergence of a pair-superfluid (pair-Luttinger liquid) phase besides the more conventional Mott-insulator and superfluid (Luttinger liquid) phases. We compute the complete phase diagram of the model by identifying characteristic properties of the pair-Luttinger liquid phase such as pair correlation functions and structure factors and find that the pair-Luttinger liquid phase is very sensitive to changes away from perfect frustration (half-flux). We provide some proposals to make the model more resilient to variants away from perfect frustration. We also study the bipartite entanglement properties of the chain. We discover that, while the scaling of the block entropy pair-superfluid and of the single-particle superfluid leads to the same central charge, the properties of the low-lying entanglement spectrum levels reveal their fundamental difference.

T. Dombre, Gabriel Kotliar

We study the optical properties of a non-Fermi-liquid phase of a generalized t-J model using a large- N expansion. This phase has a staggered distribution of fluxes in the ground state and is stabilized by a finite concentration of holes. The optical absorption is very different from the expected one in a one-band Fermi liquid and has a low-frequency Drude peak and a broad high-energy feature which scale with the concentration of holes.

Didier Poilblanc, Yasumasa Hasegawa

P. W. Anderson

We here propose the concept of generalized flux for the 3d one-band Hubbard model. These are phases in which a spontaneous vorticity proportional to the number of electrons develops self-consistently. Their properties are somewhat dissimilar from other RVB states.

D. Peter, Didier Mayou, M. Cyrot