Condensate Fraction in Neutron Matter

Abstract

We study the Bose-Einstein condensation of fermionic pairs in the uniform neutron matter by using the concept of the off-diagonal long-range order of the two-body density matrix of the system. We derive explicit formulas for the condensate density ${\rho }_c$ and the condensate fraction ${\rho }_c/\rho$ in terms of the scaled pairing energy gap $\Delta /{\epsilon }_F$, where ${\epsilon }_F$ is the Fermi energy. We calculate the condensate fraction ${\rho }_c/\rho$ as a function of the density $\rho$ by using previously obtained results for the pairing gap $\Delta$. We find the maximum condensate fraction $({\rho }_c/\rho {)}_{max}=0.42$ at the density $\rho =5.3\cdot 10^{-4}$ fm${}^{-3}$, which corresponds to the Fermi wave number $k_F=0.25$ fm${}^{-1}$.

4 pages, 3 figures, to be published in Phys. Rev. C

References in corpus (5)

• Further explorations of Skyrme-Hartree-Fock-Bogoliubov mass formulas. IX: Constraint of pairing force to ${}^1{S}_0$ neutron-matter gap
• BCS-BEC crossover of neutron pairs in symmetric and asymmetric nuclear matter
• Critical Temperature and Condensate Fraction of a Fermion Pair Condensate
• BCS-BEC Crossover and Thermodynamics in Asymmetric Nuclear Matter with Pairings in Isospin I=0 and I=1 Channels
• Superfluid properties of dilute neutron matter

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• Zero-point energy of ultracold atoms
• Finite-temperature quantum fluctuations in two-dimensional Fermi superfluids
• Superfluidity, Sound Velocity and Quasi Condensation in the 2D BCS-BEC Crossover
• BCS-BEC crossovers and unconventional phases in dilute nuclear matter
• Phase diagram of dilute nuclear matter: Unconventional pairing and the BCS-BEC crossover
• Low-density homogeneous symmetric nuclear matter: disclosing dinucleons in coexisting phases
• Pair condensation in the BCS-BEC crossover of ultracold atoms loaded onto a 2D square lattice
• From Narrow to Broad Feshbach Resonances: Condensate Fraction of Cooper Pairs and Preformed Molecules
• Fermionic condensation in ultracold atoms, nuclear matter and neutron stars
• Nuclear systems under extreme conditions: isospin asymmetry and strong B-fields