Bose-Einstein condensation of heteronuclear bound states formed in a Fermi gas of two atomic species: microscopic approach
| Autor: | Yu. V. Slyusarenko, S. V. Peletminskii, A. S. Peletminskii |
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| Jazyk: | angličtina |
| Rok vydání: | 2015 |
| Předmět: |
Physics
Condensed Matter::Quantum Gases FOS: Physical sciences Condensed Matter Physics Atomic species 01 natural sciences Atomic and Molecular Physics and Optics 010305 fluids & plasmas law.invention Heteronuclear molecule law Quantum Gases (cond-mat.quant-gas) 0103 physical sciences Bound state Atomic physics 010306 general physics Fermi gas Condensed Matter - Quantum Gases Bose–Einstein condensate |
| Popis: | We study a many-body system of interacting fermionic atoms of two species that are in thermodynamic equilibrium with their condensed heteronuclear bound states (molecules). In order to describe such an equilibrium state, we use a microscopic approach that involves the Bogoliubov model for a weakly interacting Bose gas and approximate formulation of the second quantization method in the presence of bound states of particles elaborated earlier by the authors. This microscopic approach is valid at low temperatures, when the average kinetic energy of all the components in the system is small in comparison with the bound state energy. The coupled equations, which relate the chemical potentials of fermionic components and molecular condensate density, are obtained within the proposed theory. At zero temperature, these equations are analyzed both analytically and numerically, attracting the relevant experimental data. We find the conditions at which a condensate of heteronuclear molecules coexists in equilibrium with degenerate components of a Fermi gas. The ground state energy and single-particle excitation spectrum are found. The boundaries of the applicability of the developed microscopic approach are analyzed. revised version: 24 pages, 2 figures, typos corrected, explanations added, figures re-plotted, published version |
| Databáze: | OpenAIRE |
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