2,520 research outputs found

    Effective theory and universal relations for Fermi gases near a dd-wave interaction resonance

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    In this work, we present an effective field theory to describe a two-component Fermi gas near a dd-wave interaction resonance. The effective field theory is renormalizable by matching with the low energy dd-wave scattering phase shift. Based on the effective field theory, we derive universal properties of the Fermi gas by the operator product expansion method. We find that beyond the contacts defined by adiabatic theorems, the asymptotic expressions of the momentum distribution and the Raman spectroscopy involve two extra contacts which provide additional information of correlations of the system. Our formalism sets the stage for further explorations of many-body effects in a dd-wave resonant Fermi gas. Finally we generalise our effective field theory for interaction resonances of arbitrary higher partial waves.Comment: revised versio

    Evidence for correlated states in a cluster of bosons with Rashba spin-orbit coupling

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    We study the ground state properties of spin-half bosons subjected to the Rashba spin-orbit coupling in two dimensions. Due to the enhancement of the low energy density of states, it is expected that the effect of interaction becomes more important. After reviewing several possible ideal condensed states, we carry out an exact diagonalization calculation for a cluster of the bosons in the presence of strong spin-orbit coupling on a two-dimensional disk and reveal strong correlations in its ground state. We derive a low-energy effective Hamiltonian to understand how states with strong correlations become energetically more favorable than the ideal condensed states.Comment: 23 pages, 6 figure