### Abstract

Entropy and specific heat are calculated using the spin polaron formulation at finite temperature. Our theoretical approach makes use of the Matsubara Green's function method where the interaction term in the S-matrix is the spin polaron Hamiltonian, which is constructed in a representation where holes are described as spinless fermions (holons) and spins as normal bosons. In the absence of this interaction term, the normal entropy and specific heat are obtained from the free holon thermodynamic potential and are found to resemble the BCS expressions in the low temperature regime. A second cumulant expansion of the thermodynamic potential with the spin polaron interaction yields an expression for the specific heat whose dominant term in the low temperature limit and small quasiparticle energy difference, resembles the superconducting-state electronic specific heat of the BCS theory.

Original language | English |
---|---|

Pages (from-to) | 283-287 |

Number of pages | 5 |

Journal | Journal of Superconductivity and Novel Magnetism |

Volume | 17 |

Issue number | 2 |

Publication status | Published - 2004 |

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### Keywords

- Entropy
- Matsubara Green's function
- Specific heat
- Spin polaron
- Thermodynamic potential

### ASJC Scopus subject areas

- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Physics and Astronomy (miscellaneous)

### Cite this

*Journal of Superconductivity and Novel Magnetism*,

*17*(2), 283-287.

**Calculation of entropy and specific heat in the spin polaron formulation at finite temperature.** / Morales, A. A.; Yanga, D. M.; Kurihara, S.

Research output: Contribution to journal › Article

*Journal of Superconductivity and Novel Magnetism*, vol. 17, no. 2, pp. 283-287.

}

TY - JOUR

T1 - Calculation of entropy and specific heat in the spin polaron formulation at finite temperature

AU - Morales, A. A.

AU - Yanga, D. M.

AU - Kurihara, S.

PY - 2004

Y1 - 2004

N2 - Entropy and specific heat are calculated using the spin polaron formulation at finite temperature. Our theoretical approach makes use of the Matsubara Green's function method where the interaction term in the S-matrix is the spin polaron Hamiltonian, which is constructed in a representation where holes are described as spinless fermions (holons) and spins as normal bosons. In the absence of this interaction term, the normal entropy and specific heat are obtained from the free holon thermodynamic potential and are found to resemble the BCS expressions in the low temperature regime. A second cumulant expansion of the thermodynamic potential with the spin polaron interaction yields an expression for the specific heat whose dominant term in the low temperature limit and small quasiparticle energy difference, resembles the superconducting-state electronic specific heat of the BCS theory.

AB - Entropy and specific heat are calculated using the spin polaron formulation at finite temperature. Our theoretical approach makes use of the Matsubara Green's function method where the interaction term in the S-matrix is the spin polaron Hamiltonian, which is constructed in a representation where holes are described as spinless fermions (holons) and spins as normal bosons. In the absence of this interaction term, the normal entropy and specific heat are obtained from the free holon thermodynamic potential and are found to resemble the BCS expressions in the low temperature regime. A second cumulant expansion of the thermodynamic potential with the spin polaron interaction yields an expression for the specific heat whose dominant term in the low temperature limit and small quasiparticle energy difference, resembles the superconducting-state electronic specific heat of the BCS theory.

KW - Entropy

KW - Matsubara Green's function

KW - Specific heat

KW - Spin polaron

KW - Thermodynamic potential

UR - http://www.scopus.com/inward/record.url?scp=3543105042&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=3543105042&partnerID=8YFLogxK

M3 - Article

VL - 17

SP - 283

EP - 287

JO - Journal of Superconductivity and Novel Magnetism

JF - Journal of Superconductivity and Novel Magnetism

SN - 1557-1939

IS - 2

ER -