Mott criticality and pseudogap in Bose-Fermi mixtures
arXiv:1205.4026 · doi:10.1103/PhysRevLett.109.235304
Abstract
We study the Mott transition of a mixed Bose-Fermi system of ultracold atoms in an optical lattice, where the number of (spinless) fermions and bosons adds up to one atom per lattice, n_F+n_B=1. For weak interactions, a Fermi surface coexists with a Bose-Einstein condensate while for strong interaction the system is incompressible but still characterized by a Fermi surface of composite fermions. At the critical point, the spectral function of the fermions, A(k,w), exhibits a pseudo-gapped behavior, rising as |w| at the Fermi momentum, while in the Mott phase it is fully gapped. Taking into account the interaction between the critical modes leads at very low temperatures either to p-wave pairing or the transition is driven weakly first order. The same mechanism should also be important in antiferromagnetic metals with a small Fermi surface.
5 pages, 3 figures + supplementary material. Corrected typo in Eq. (7): added previously omitted term
References in corpus (13)
- Using photoemission spectroscopy to probe a strongly interacting Fermi gas
- U(1) Gauge Theory of the Hubbard Model : Spin Liquid States and Possible Application to k-(BEDT-TTF)_2 Cu_2 (CN)_3
- Quantum phase transitions of metals in two spatial dimensions: I. Ising-nematic order
- Radiofrequency spectroscopy of a strongly interacting two-dimensional Fermi gas
- Critical fermi surfaces and non-fermi liquid metals
- Theory of a continuous Mott transition in two dimensions
- Interaction and filling induced quantum phases of dual Mott insulators of bosons and fermions
- Supersolid Bose-Fermi Mixtures in Optical Lattices
- Supersymmetry and Goldstino-like Mode in Bose-Fermi Mixtures
- Strongly coupled quantum criticality with a Fermi surface in two dimensions: fractionalization of spin and charge collective modes
- Creating p-wave superfluids and topological excitations in optical lattices
- Controlled hole doping of a Mott insulator of ultracold fermionic atoms
- Superfluid-Insulator Transition and Fermion Pairing in Bose-Fermi Mixtures