### Abstract

We investigate de Haas-van Alphen (dHvA) oscillations in the mixed state of a type-II two-dimensional superconductor within a self-consistent Gor'kov perturbation scheme. Assuming that the order parameter forms a vortex lattice we can calculate the expansion coefficients exactly to any order. We have tested the results of the perturbation theory to fourth and eighth order against an exact numerical solution of the corresponding Bogoliubov-de Gennes equations. The perturbation theory is found to describe well the onset of superconductivity close to the transition point H_{c2}. Contrary to earlier calculations by other authors we do not find that the perturbative scheme predicts any maximum of the dHvA oscillations below H_{c2}. Instead we obtain a substantial damping of the magnetic oscillations in the mixed state as compared to the normal state. We have examined the effect of an oscillatory chemical potential due to particle conservation and the effect of a finite Zeeman splitting. Furthermore, we have investigated the recently debated issue of the possibility of a sign change of the fundamental harmonic of the magnetic oscillations. Our theory is compared with experiment and we have found good agreement.

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

Pages (from-to) | 809-825 |

Number of pages | 17 |

Journal | Physical Review B - Condensed Matter and Materials Physics |

Volume | 56 |

Issue number | 2 |

State | Published - Jul 1 1997 |

Externally published | Yes |

### Fingerprint

### ASJC Scopus subject areas

- Condensed Matter Physics

### Cite this

*Physical Review B - Condensed Matter and Materials Physics*,

*56*(2), 809-825.

**Ginzburg-Landau-Gor'kov theory of magnetic oscillations in a type-II two-dimensional superconductor.** / Bruun, G. M.; Nicopoulos, V. Nikos; Johnson, Neil F.

Research output: Contribution to journal › Article

*Physical Review B - Condensed Matter and Materials Physics*, vol. 56, no. 2, pp. 809-825.

}

TY - JOUR

T1 - Ginzburg-Landau-Gor'kov theory of magnetic oscillations in a type-II two-dimensional superconductor

AU - Bruun, G. M.

AU - Nicopoulos, V. Nikos

AU - Johnson, Neil F

PY - 1997/7/1

Y1 - 1997/7/1

N2 - We investigate de Haas-van Alphen (dHvA) oscillations in the mixed state of a type-II two-dimensional superconductor within a self-consistent Gor'kov perturbation scheme. Assuming that the order parameter forms a vortex lattice we can calculate the expansion coefficients exactly to any order. We have tested the results of the perturbation theory to fourth and eighth order against an exact numerical solution of the corresponding Bogoliubov-de Gennes equations. The perturbation theory is found to describe well the onset of superconductivity close to the transition point Hc2. Contrary to earlier calculations by other authors we do not find that the perturbative scheme predicts any maximum of the dHvA oscillations below Hc2. Instead we obtain a substantial damping of the magnetic oscillations in the mixed state as compared to the normal state. We have examined the effect of an oscillatory chemical potential due to particle conservation and the effect of a finite Zeeman splitting. Furthermore, we have investigated the recently debated issue of the possibility of a sign change of the fundamental harmonic of the magnetic oscillations. Our theory is compared with experiment and we have found good agreement.

AB - We investigate de Haas-van Alphen (dHvA) oscillations in the mixed state of a type-II two-dimensional superconductor within a self-consistent Gor'kov perturbation scheme. Assuming that the order parameter forms a vortex lattice we can calculate the expansion coefficients exactly to any order. We have tested the results of the perturbation theory to fourth and eighth order against an exact numerical solution of the corresponding Bogoliubov-de Gennes equations. The perturbation theory is found to describe well the onset of superconductivity close to the transition point Hc2. Contrary to earlier calculations by other authors we do not find that the perturbative scheme predicts any maximum of the dHvA oscillations below Hc2. Instead we obtain a substantial damping of the magnetic oscillations in the mixed state as compared to the normal state. We have examined the effect of an oscillatory chemical potential due to particle conservation and the effect of a finite Zeeman splitting. Furthermore, we have investigated the recently debated issue of the possibility of a sign change of the fundamental harmonic of the magnetic oscillations. Our theory is compared with experiment and we have found good agreement.

UR - http://www.scopus.com/inward/record.url?scp=0642272557&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0642272557&partnerID=8YFLogxK

M3 - Article

AN - SCOPUS:0642272557

VL - 56

SP - 809

EP - 825

JO - Physical Review B-Condensed Matter

JF - Physical Review B-Condensed Matter

SN - 1098-0121

IS - 2

ER -