### Abstract

The most popular description of superconductivity phenomenon in Sr_{2}RuO_{4} is based on a so-called single-band (usually γ-band) "isotropic p-wave order parameter". In a magnetic field parallel to the conducting planes, such triplet "isotropic p-wave phase" is not destroyed by the Clogston-Chandrasekhar paramagnetic limiting field and can be destroyed only by the Meissner currents (i.e., the orbital effects). We analyze the orbital destructive effects against superconductivity for in-plane magnetic field (when electron orbits are open) and find that H_{c2}^{∥}(0) ≃ 0.75 T_{c}(dH_{c2}^{∥}(T)/dT)_{Tc} (which is a little bigger than the Werthamer-Helfand-Hohenberg value for an isotropic 3D case). We point out that the experimentally determined ratio H_{c2}^{∥}(0)/T_{c}(dH_{c2} ^{∥}(T)/dT)T_{c} ≃ 0.44 - 0.5 in Sr_{2}RuO_{4} is significantly less than the calculated value 0.75. Since the upper critical field, K_{c2}^{∥}(T). is a well experimentally defined quantity in Sr_{2}RuO_{4} (unlike high-T_{c} superconductors) we conclude that the single-band triplet "isotropic p-wave order parameter" seems to be inappropriate description of superconductivity in this material. Two possibilities are discussed: 1) Three-band nature of triplet superconductivity; 2) Singlet (d-wave) nature of superconducting pairing (in this case, the destructive actions of both the orbital effects and the Clogston-Chandrasekhar paramagnetic effects result in an agreement with the experimentally observed value of H_{c2}^{∥}(0)/T_{c}(dH_{c2} ^{∥}(T)/dT)_{Tc}).

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

Pages (from-to) | 1677-1678 |

Number of pages | 2 |

Journal | Physica C: Superconductivity and its Applications |

Volume | 341-348 |

Issue number | PART 2 |

State | Published - 2000 |

Externally published | Yes |

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### ASJC Scopus subject areas

- Condensed Matter Physics

### Cite this

_{2}RuO

_{4}: A triplet scenario versus a singlet one.

*Physica C: Superconductivity and its Applications*,

*341-348*(PART 2), 1677-1678.

**Paramagnetic-like destructive mechanism against superconductivity in Sr _{2}RuO_{4} : A triplet scenario versus a singlet one.** / Lebed, Andrei G; Hayashi, Nobuhiko.

Research output: Contribution to journal › Article

_{2}RuO

_{4}: A triplet scenario versus a singlet one',

*Physica C: Superconductivity and its Applications*, vol. 341-348, no. PART 2, pp. 1677-1678.

_{2}RuO

_{4}: A triplet scenario versus a singlet one. Physica C: Superconductivity and its Applications. 2000;341-348(PART 2):1677-1678.

}

TY - JOUR

T1 - Paramagnetic-like destructive mechanism against superconductivity in Sr2RuO4

T2 - A triplet scenario versus a singlet one

AU - Lebed, Andrei G

AU - Hayashi, Nobuhiko

PY - 2000

Y1 - 2000

N2 - The most popular description of superconductivity phenomenon in Sr2RuO4 is based on a so-called single-band (usually γ-band) "isotropic p-wave order parameter". In a magnetic field parallel to the conducting planes, such triplet "isotropic p-wave phase" is not destroyed by the Clogston-Chandrasekhar paramagnetic limiting field and can be destroyed only by the Meissner currents (i.e., the orbital effects). We analyze the orbital destructive effects against superconductivity for in-plane magnetic field (when electron orbits are open) and find that Hc2∥(0) ≃ 0.75 Tc(dHc2∥(T)/dT)Tc (which is a little bigger than the Werthamer-Helfand-Hohenberg value for an isotropic 3D case). We point out that the experimentally determined ratio Hc2∥(0)/Tc(dHc2 ∥(T)/dT)Tc ≃ 0.44 - 0.5 in Sr2RuO4 is significantly less than the calculated value 0.75. Since the upper critical field, Kc2∥(T). is a well experimentally defined quantity in Sr2RuO4 (unlike high-Tc superconductors) we conclude that the single-band triplet "isotropic p-wave order parameter" seems to be inappropriate description of superconductivity in this material. Two possibilities are discussed: 1) Three-band nature of triplet superconductivity; 2) Singlet (d-wave) nature of superconducting pairing (in this case, the destructive actions of both the orbital effects and the Clogston-Chandrasekhar paramagnetic effects result in an agreement with the experimentally observed value of Hc2∥(0)/Tc(dHc2 ∥(T)/dT)Tc).

AB - The most popular description of superconductivity phenomenon in Sr2RuO4 is based on a so-called single-band (usually γ-band) "isotropic p-wave order parameter". In a magnetic field parallel to the conducting planes, such triplet "isotropic p-wave phase" is not destroyed by the Clogston-Chandrasekhar paramagnetic limiting field and can be destroyed only by the Meissner currents (i.e., the orbital effects). We analyze the orbital destructive effects against superconductivity for in-plane magnetic field (when electron orbits are open) and find that Hc2∥(0) ≃ 0.75 Tc(dHc2∥(T)/dT)Tc (which is a little bigger than the Werthamer-Helfand-Hohenberg value for an isotropic 3D case). We point out that the experimentally determined ratio Hc2∥(0)/Tc(dHc2 ∥(T)/dT)Tc ≃ 0.44 - 0.5 in Sr2RuO4 is significantly less than the calculated value 0.75. Since the upper critical field, Kc2∥(T). is a well experimentally defined quantity in Sr2RuO4 (unlike high-Tc superconductors) we conclude that the single-band triplet "isotropic p-wave order parameter" seems to be inappropriate description of superconductivity in this material. Two possibilities are discussed: 1) Three-band nature of triplet superconductivity; 2) Singlet (d-wave) nature of superconducting pairing (in this case, the destructive actions of both the orbital effects and the Clogston-Chandrasekhar paramagnetic effects result in an agreement with the experimentally observed value of Hc2∥(0)/Tc(dHc2 ∥(T)/dT)Tc).

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M3 - Article

VL - 341-348

SP - 1677

EP - 1678

JO - Physica C: Superconductivity and its Applications

JF - Physica C: Superconductivity and its Applications

SN - 0921-4534

IS - PART 2

ER -