Flux penetration in an antiferromagnetic layered superconductor

2006

Acta Phys. Pol. A

It might be possible that in high temperature layered antiferromagnetic supeconductors an applied magnetic field causes the mixed state to be composed of Josephson vortices possessing magnetic domains. We discuss how this new kind of vortices moves through the intrinsic pinning potential and calculate their activation energy of thermal as well as quantum excitation. We show a possible new phenomenon of crossover from quantum to thermal creep in constant temperature forced by the change of intensity of the external field, or by the change of its direction in the basal plane of layered structure.

Section: Quantum Activation Of the Magnetic Fluxmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 97%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Dynamics of the Magnetic Flux Peculiar to Antiferromagnetic Superconductors

2006

Acta Phys. Pol. A

“…This field may be thought as the second critical field for flux penetration calculated in the single vortex approximation 30 . Combining Eqs.…”

Section: Two Step Flux Penetrationmentioning

confidence: 99%

Two-step flux penetration in layered antiferromagnetic superconductor

Physica C: Superconductivity

2003

The paper reviews a concept of induced spin-flop domain inside vortices in an antiferromagnetic superconductor. Such phenomenon may occur when an external magnetic field is strong enough to flip over magnetic moments in the core of the vortex from their ground state configuration. The formation of the domain structure inside vortices modifies the surface energy barrier of the superconductor. During this process the entrance of the flux is stopped and a newly created state exhibits perfect shielding. Such behavior should be visible as a plateau on the dependence of flux density as a function of the external magnetic field. The end of the plateau determines the critical field, which has been called the second critical field for flux penetration. Moreover, it is predicted and described how this phenomenon modifies flux creep in layered superconductors. The various scenarios of changing the creep regime from thermal to quantum and vice versa at constant temperature are discussed. PACS numbers: 74.60.-w, 74.25.Ha.

“…In the present model (see also [9]) we come across two following situations: 1. The external magnetic field is pointing in the b direction and exceeds H T in the vortex core.…”

Section: Introductionmentioning

confidence: 99%

Intrinsic pinning in layered antiferromagnetic superconductor

Physica C: Superconductivity

1998

Self Cite

The intrinsic pinning in high-temperature superconductor with long range antiferromagnetic order of rare-earth ions confined to the isolating planes is described. The interaction of antiferromagnetic and superconducting subsystems in the mixed state may lead to the creation of spin-flop domain along the vortex core. It is shown that the behavior of several physical quantities such as magnetization, activation energy, current-voltage characteristic and flux creep changes when the direction of the external field changes in the basal a-b plane. It is also shown that the decay of the trapped flux is logarithmic function of time.