Dissipative macroscopic quantum tunneling in type-I superconductors

Zarzuela, Ricardo; Chudnovsky, Eugene M.; Tejada, J.

doi:10.1103/physrevb.84.184525

Cited by 4 publications

(2 citation statements)

References 33 publications

(39 reference statements)

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“…Several physical properties of the system, like the average size of the energy barriers, the average characteristic lengths of the bumps, and the crossover temperature between thermal and non-thermal regimes of magnetic relaxation, were thus determined [20]. Moreover, a mathematical model that describes a dissipative quantum escape of a two-dimensional manifold from a planar potential well, which corresponds to a current-driven quantum depinning of a NSI in a type-I superconductor, has been very recently developed and has proven to match successfully the experimental results obtained in Pb [21].…”

Section: Introductionmentioning

confidence: 88%

The role of temperature in the magnetic irreversibility of type-I Pb superconductors

Vélez

García-Santiago²,

Hernández³

et al. 2012

J. Phys.: Condens. Matter

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Evidence of how temperature plays a role in the magnetic irreversibility in the intermediate state of a cylinder and various disks of pure type-I superconducting lead is presented. Isothermal measurements of first magnetization curves and hysteresis cycles are analyzed in a reduced representation that defines an equilibrium state for flux penetration in all the samples and reveals that flux expulsion depends on temperature in the disks but not in the cylinder. The magnetic field at which irreversibility sets in along the descending branch of the cycle and the remnant magnetization at zero field are found to decrease with temperature. The contributions to irreversibility of the geometrical barrier and the energy minima associated with stress defects that act as pinning centers on normal-superconductor interfaces are discussed in an effort to account for the results obtained.

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Section: Introductionmentioning

confidence: 88%

The role of temperature in the magnetic irreversibility of type-I Pb superconductors

Vélez

García-Santiago²,

Hernández³

et al. 2012

J. Phys.: Condens. Matter

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“…Macroscopic quantum tunneling of mesoscopic solidstate objects has been intensively studied in the past. Examples include single domain particles [1][2][3] , domain walls in magnets [4][5][6] , magnetic clusters 7,8 , flux lines in type-II superconductors 9,10 and normal-superconducting interfaces in type-I superconductors 11,12 . It is well known that micron-size circular disks made of soft ferromagnetic materials exhibit the vortex state as the ground state of the system for a wide variety of diameters and thicknesses [13][14][15] .…”

Section: Introductionmentioning

confidence: 99%

Quantum dynamics of vortices in mesoscopic magnetic disks

et al. 2013

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Model of quantum depinning of magnetic vortex cores from line defects in a disk geometry and under the application of an in-plane magnetic field has been developed within the framework of the Caldeira-Leggett theory. The corresponding instanton solutions are computed for several values of the magnetic field. Expressions for the crossover temperature Tc and for the depinning rate Γ(T ) are obtained. Fitting of the theory parameters to experimental data is also presented.

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Magnetic field dependence of the quantum tunneling of normal-superconductor interfaces in a type-I Pb superconductor

Vélez¹,

Zarzuela²,

García-Santiago³

et al. 2012

Phys. Rev. B

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We report experimental evidence of the effect of an applied magnetic field on the non-thermal magnetic relaxation in a disk-shaped type-I lead superconductor. The time evolution of the irreversible magnetization proves to be logarithmic for a wide range of temperatures and magnetic field values along the descending branch of the hysteresis cycle. When the intensity of the magnetic field increases, the crossover temperature separating the thermal and non-thermal regimes of magnetic relaxation is found to decrease, whereas the rate at which such relaxation occurs is observed to increase. These results are discussed in the framework of a recent model for quantum tunneling of normal-superconductor interfaces through the distribution of pinning energy barriers generated by structural defects in the sample, considering that the strength of the barriers decreases with the magnetic field. A phase diagram describing the dynamics of interfaces during flux expulsion in the intermediate state as a function of temperature and magnetic field is constructed.

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Dissipative macroscopic quantum tunneling in type-I superconductors

Cited by 4 publications

References 33 publications

The role of temperature in the magnetic irreversibility of type-I Pb superconductors

The role of temperature in the magnetic irreversibility of type-I Pb superconductors

Quantum dynamics of vortices in mesoscopic magnetic disks

Magnetic field dependence of the quantum tunneling of normal-superconductor interfaces in a type-I Pb superconductor

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