Composite Fermions and Quartets in Optical Traps and in High-Tc Superconductors

Abstract

We consider a possibility of the creation of composite fermions in optical traps and in high‐Tc superconductors. For optical traps we study a model of Fermi‐Bose mixture with resonant attraction between particles of different sorts. In this case a pairing between fermion and boson of the type bf is possible. This pairing corresponds to creation of composite fermions. At low temperatures and equal densities of fermions and bosons composite fermions are further paired in quartets. In the 2D case we exactly solve Skorniakov‐Ter‐Martirosian type of integral equations and find the binding energies of two bosons plus one fermion fbb and two bosons plus two fermions fbfb. For high‐Tc superconductors we consider a quartet — a bound state of two composite holes Δ =〈 hh 〉, where each composite hole h = fb consists of a spinon and a holon bound by the stringlike potential. Our investigations are important for recent experiments on the observation of weakly bound composite fermions and bosons in optical traps in the ...