Tomasz Krzyszton

Isolated vortex line in an antiferromagnetic superconductor

Abstract The Ginzburg-Landau theory and micromagnetic theory of antiferromagnetism are applied to study a magnetic structure of isolated flux line in an antiferromagnetic superconductor of type II. The structure consists of three coaxial domains in which paramagnetic, spin-flop and antiferromagnetic phases coexist with superconductivity. The paper explains recent neutron scattering experiments on Dy1.2Mo6S8 and Tb1.2Mo6S8.

Possibility of two-stage flux penetration in antiferromagnetic superconductors

Abstract An induced ferromagnetism in antiferromagnetic superconductors is possible, caused by a magnetic structure of vortex lines appearing in an external magnetic field strong enough to “flip over” the spins in the vortex core from their antiferromagnetic configuration. If the magnetic field is less than the “flip over” field the vortex line is entirely in the antiferromagnetic phase. Therefore the vortex interaction with the surface of a sample is altered when an applied magnetic field exceeds the “flip over” field. This mechanism makes the appearance of a new energy barrier that strongly influences the flux penetration possible. An estimation of the second critical entry field is made for DyMo 6 S 8 .

Flux penetration in an antiferromagnetic layered superconductor

Abstract A layered superconductor with long-range antiferromagnetic order of rare earth ions confined to isolating planes is described. It is argued that the process of flux penetration along the a and b axes may be different due to the possibility of creation of a spin-flop domain along the vortex core.

Two-step flux penetration in classic antiferromagnetic superconductor

Abstract:The influence of antiferromagnetic order on the mixed state of a superconductor may result in creation of spin-flop domains along vortices. This may happen when an external magnetic field is strong enough to flip over magnetic moments in the vortex core from their ground state configuration. The formation of domain structure causes modification of the surface energy barrier, and creation of the new state in which magnetic flux density is independent of the applied field. The modified surface energy barrier has been calculated for parameters of the antiferromagnetic superconductor DyMo6S8. The prediction of two-step flux penetration process has been verified by precise magnetization measurements performed on the single crystal of DyMo6S8 at milikelvin temperatures. A characteristic plateau on the virgin curve B(H0) has been found and attributed to the modified surface energy barrier. The end of the plateau determines the critical field, which we call the second critical field for flux penetration.The influence of antiferromagnetic order on the mixed state of a superconductor may result in creation of spin-flop domains along vortices. This may happen when an external magnetic field is strong enough to flip over magnetic moments in the vortex core from their ground state configuration. The formation of domain structure causes modification of the surface energy barrier, and creation of the new state in which magnetic flux density is independent of the applied field. The modified surface energy barrier has been calculated for parameters of the antiferromagnetic superconductor DyMo

Crossover from thermal to quantum creep in layered antiferromagnetic superconductor

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Two-step flux penetration in layered antiferromagnetic superconductor

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Intrinsic pinning in layered antiferromagnetic superconductor

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Magnetic Flux Penetration and Motion in Antiferromagnetic Superconductors

. The prediction of two-step flux penetration process has been verified by precise magnetization measurements performed on the single crystal of DyMo

Anomalous magnetization of antiferromagnetic layered superconductor

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Vortex penetration in the uniaxial anisotropic superconductor

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