### Abstract

Using universal properties and a basic statistical mechanical approach, we propose a general equation of state for unitary Fermi gases. The universal equation of state is written as a series solution to a self consistent integral equation where the general solution is a linear combination of Fermi functions. First, by truncating our series solution to four terms with already known exact theoretical inputs at limiting cases, namely the first three virial coefficients and using the Bertsch parameter as a free parameter, we find a good agreement with experimental measurements in the entire temperature region in the normal state. This analytical equation of state agrees with experimental data up to the fugacity z = 18, which is a vast improvement over the other analytical equations of state available where the agreements is only up to . Second, by truncating our series solution to four terms again using first four virial coefficients, we find the Bertsch parameter , which is in good agreement with the direct experimental measurement of . This second form of equation of state shows a good agreement with self-consistent T-matrix calculations in the normal phase.

Original language | English (US) |
---|---|

Article number | 225301 |

Journal | Journal of Physics B: Atomic, Molecular and Optical Physics |

Volume | 49 |

Issue number | 22 |

DOIs | |

State | Published - Oct 24 2016 |

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### Keywords

- Fermi gases
- equation of state
- universal Fermions

### ASJC Scopus subject areas

- Atomic and Molecular Physics, and Optics
- Condensed Matter Physics

### Cite this

**An effective series expansion to the equation of state of unitary Fermi gases.** / DeSilva, Theja Nilantha.

Research output: Contribution to journal › Article

}

TY - JOUR

T1 - An effective series expansion to the equation of state of unitary Fermi gases

AU - DeSilva, Theja Nilantha

PY - 2016/10/24

Y1 - 2016/10/24

N2 - Using universal properties and a basic statistical mechanical approach, we propose a general equation of state for unitary Fermi gases. The universal equation of state is written as a series solution to a self consistent integral equation where the general solution is a linear combination of Fermi functions. First, by truncating our series solution to four terms with already known exact theoretical inputs at limiting cases, namely the first three virial coefficients and using the Bertsch parameter as a free parameter, we find a good agreement with experimental measurements in the entire temperature region in the normal state. This analytical equation of state agrees with experimental data up to the fugacity z = 18, which is a vast improvement over the other analytical equations of state available where the agreements is only up to . Second, by truncating our series solution to four terms again using first four virial coefficients, we find the Bertsch parameter , which is in good agreement with the direct experimental measurement of . This second form of equation of state shows a good agreement with self-consistent T-matrix calculations in the normal phase.

AB - Using universal properties and a basic statistical mechanical approach, we propose a general equation of state for unitary Fermi gases. The universal equation of state is written as a series solution to a self consistent integral equation where the general solution is a linear combination of Fermi functions. First, by truncating our series solution to four terms with already known exact theoretical inputs at limiting cases, namely the first three virial coefficients and using the Bertsch parameter as a free parameter, we find a good agreement with experimental measurements in the entire temperature region in the normal state. This analytical equation of state agrees with experimental data up to the fugacity z = 18, which is a vast improvement over the other analytical equations of state available where the agreements is only up to . Second, by truncating our series solution to four terms again using first four virial coefficients, we find the Bertsch parameter , which is in good agreement with the direct experimental measurement of . This second form of equation of state shows a good agreement with self-consistent T-matrix calculations in the normal phase.

KW - Fermi gases

KW - equation of state

KW - universal Fermions

UR - http://www.scopus.com/inward/record.url?scp=84994589259&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84994589259&partnerID=8YFLogxK

U2 - 10.1088/0953-4075/49/22/225301

DO - 10.1088/0953-4075/49/22/225301

M3 - Article

VL - 49

JO - Journal of Physics B: Atomic, Molecular and Optical Physics

JF - Journal of Physics B: Atomic, Molecular and Optical Physics

SN - 0953-4075

IS - 22

M1 - 225301

ER -