arXiv:cond-mat/0112354 · Physical Review A

Boson-induced s -wave pairing in dilute boson-fermion mixtures

Luciano Viverit

Published Aug 15, 2002• 64 citations

Abstract

We show that in dilute boson-fermion mixtures with fermions in two internal states, even when the bare fermion-fermion interaction is repulsive, the exchange of density fluctuations of the Bose condensate may lead to an effective fermion-fermion attraction, and thus to a Cooper instability in the s-wave channel. We give a simple condition to know when this is going to happen, and an analytic expression for the associated ${T}_{c}$ in the most important limit where the phonon branch of the Bogoliubov excitation spectrum of the bosons is important. We find a ${T}_{c}$ of the same order as for a pure Fermi gas with bare attraction.

DOI: 10.1103/physreva.66.023605

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arXiv:cond-mat/0112354 · Physical Review A

Boson-induced s -wave pairing in dilute boson-fermion mixtures

Luciano Viverit

Published Aug 15, 2002• 64 citations

arXiv HTML PDF

Abstract

{T}_{c}

in the most important limit where the phonon branch of the Bogoliubov excitation spectrum of the bosons is important. We find a

{T}_{c}

of the same order as for a pure Fermi gas with bare attraction.

DOI: 10.1103/physreva.66.023605

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{T}_{c}

in the most important limit where the phonon branch of the Bogoliubov excitation spectrum of the bosons is important. We find a

{T}_{c}

of the same order as for a pure Fermi gas with bare attraction.

l

channels. It has been found that the onset of the superconducting phase can occur at temperatures

(>100\mathrm{nK})

of the same order of magnitude as the Fermi temperature $(\ensuremath{\sim}300\mathrm{nK}),$ and the energy gap in the excitation spectrum is a small fraction $(\ensuremath{\sim}1%)$ of the Fermi energy.

T_c \propto g

as opposed to

T_c \propto \exp(-1/g)

for the BCS case. The dilute bose gas density acts as the primary bottleneck to the enhancement. We discuss the conceptual difficulties of implementing this idea in electron-exciton mixtures.