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arXiv · 1007.2891

Rotons in a hybrid Bose-Fermi system

I. A. Shelykh·T. Taylor·A. V. Kavokin
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Abstract

We calculate the spectrum of elementary excitations in a two-dimensional exciton superfluid in the vicinity of a two-dimensional electron gas. We show that attraction of excitons due to their scattering with free electrons may lead to formation of a roton minimum. The energy of this minimum may go below the ground state energy which manifests breaking of the superfluidity. The Berezinsky-Kosterlitz-Thouless phase transition temperature decreases due to the exciton-exciton attraction mediated by electrons.

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I. A. Shelykh, T. Taylor, A. V. Kavokin. 2010-09-03. Rotons in a hybrid Bose-Fermi system. https://doi.org/10.1103/physrevlett.105.140402

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