Nonlinear magnetization of<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msub><mml:mrow><mml:mi mathvariant="normal">YBa</mml:mi></mml:mrow><mml:mrow><mml:mn>2</mml:mn></mml:mrow></mml:msub></mml:mrow></mml:math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msub><mml:mrow><mml:mi mathvariant="normal">Cu</mml:mi></mml:mrow><mml:mrow><mml:mn>3</mml:mn></mml:mrow></mml:msub></mml:mrow></mml:math><mml:math xmlns:mml="http://ww

Ciccarello, I.; Fazio, Claudio; Guccione, M.; Vigni, M. Li; Trunin, M. R.

doi:10.1103/physrevb.49.6280

Cited by 28 publications

(14 citation statements)

References 13 publications

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“…[1] All superconductors have an intrinsic nonlinearity associated with the nonlinear Meissner effect (NLME). Calculations of harmonic response based on BCS theory, [2,3] Ginzburg-Landau (GL) theory, [4] and microwave field-induced modulation of the super/normal fluid densities near T c [5] have been proposed to describe the intrinsic nonlinearities of superconductors. Extrinsic sources of nonlinearity include grain boundaries, [6] edge effects, and weakly-coupled grains.…”

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confidence: 99%

Spatially-resolved nonlinearity measurements of YBa2Cu3O7−δ bicrystal grain boundaries

Lee

Anlage

2003

Applied Physics Letters

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We have developed a near-field microwave microscope to locally excite a superconducting film and measure second and third harmonic responses at microwave frequencies. We study the local nonlinear response of a YBa2Cu3O 7−δ thin film grown on a bi-crystal SrTiO3 substrate. The location of the bi-crystal grain boundary is clearly identified by the microscope through higher harmonic response, and the spatial resolution is on the order of the magnetic loop probe size, about 500µm. The harmonic power and spatial resolution are successfully modeled with a onedimensional extended Josephson junction simulation. From the model, the 2nd order harmonic response is dominated by Josephson vortex generation and flow. A geometry-free nonlinear scaling current density JNL ≃ 10 4 ∼ 10 5 A/cm 2 is also extracted from the data, indicating that the grain boundary weak link is the dominant nonlinear source in this case.PACS numbers: PACS: 74.25. Fy, 74.25.Nf, 74.62.Dh, 74.72.Bk The nonlinear properties of high-T c superconductors have been of great concern in microwave applications, although the microscopic origins of the nonlinear response still remain uncertain. [7] Many experiments have studied the intermodulation power, [8,9] harmonic generation, [10,11] or the nonlinear surface impedance of superconductors [12,13] as a function of applied microwave power. However, most nonlinear experiments are done with resonant techniques, which by their nature study the averaged nonlinear response from the whole sample rather than locally. Such techniques usually have difficulty in either avoiding edge effects, which give undesired vortex entry, or in identifying the microscopic nonlinear sources. Therefore, a technique capable of locally measuring nonlinear properties of samples is necessary for understanding the physics of different nonlinear mechanisms. In addition, most existing experimental techniques focus on 3rd order nonlinearities, which can be conveniently studied by intermodulation techniques, but rarely address the 2nd order nonlinear response. Here we present a technique to locally characterize 2nd and 3rd order nonlinearities through spatially localized harmonic generation.In prior work, [9] we studied the intermodulation signal from a high-T c superconducting microwave resonator * Electronic address: sycamore@wam.umd.edu † Electronic address: anlage@squid.umd.edu using a scanned electric field pick-up probe. Both the "global" and the "local" intermodulation power measured with the open-end coaxial probe were presented. However, the local measurements were actually a superposition of nonlinear responses that were generated locally but propagated throughout the microstrip and formed a resonant standing-wave pattern. To avoid this loss of spatial information, we have developed a non-resonant near-field microwave microscope, to nondestructively measure the local harmonic generation from un-patterned samples. This technique has the additional advantage of operating equally well through T c and into the normal state of the sample...

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Spatially-resolved nonlinearity measurements of YBa2Cu3O7−δ bicrystal grain boundaries

Lee

Anlage

2003

Applied Physics Letters

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“…At magnetic fields higher than the lower critical field, when the weak links are decoupled, harmonic emission has been ascribed to intragrain-fluxon dynamics [21,22]. At temperatures near T c , modulation of the order parameter by the em field is the main source of nonlinearity [23,24,25]. To our knowledge, none of the models reported up to now in the literature discuss relaxation phenomena in the em response.…”

Section: Discussionmentioning

confidence: 86%

“…Nonlinear electromagnetic response of both conventional and high-T c superconductors has been discussed by different authors [16,17,18,19,20,21,22,23,24,25]. Several mechanisms give rise to emission of signals oscillating at harmonic frequencies of the driving field.…”

Section: Discussionmentioning

confidence: 99%

Surface-barrier effects in the microwave second-harmonic response of superconductors in the mixed state

et al. 2005

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Abstract. We report on transient effects in the microwave second-order response of different type of superconductors in the mixed state. The samples have contemporarily been exposed to a dc magnetic field, varying with a constant rate of 60 Oe/s, and a pulsed microwave magnetic field. The time evolution of the signal radiated at the second-harmonic frequency of the driving field has been measured for about 500 s from the instant in which the dc-field sweep has been stopped, with sampling time of ∼ 0.3 s. We show that the second-harmonic signal exhibits two relaxation regimes; an initial exponential decay, which endures roughly 10 s, and a logarithmic decay in the time scale of minutes. Evidence is given that the decay in the time scale of minutes is ruled by magnetic relaxation over the surface barrier.PACS. 74.25.Ha Magnetic properties -74.25.Nf Response to electromagnetic fields (nuclear magnetic resonance, surface impedance, etc.) -74

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“…It is well known that superconducting materials, especially high-T c superconductors, when exposed to intense electromagnetic fields, show an enhanced nonlinear response [1][2][3][4][5][6][7][8][9][10][11][12].…”

Section: Introductionmentioning

confidence: 99%

Time evolution of the microwave second-order response of YBaCuO powder

Gallitto

Ciccarello

Coronnello

et al. 2004

Physica C: Superconductivity

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Nonlinear magnetization ofYBa2Cu3
I. Ciccarello
¹
,
Claudio Fazio
²
,
M. Guccione
³

et al.

Cited by 28 publications

References 13 publications

Spatially-resolved nonlinearity measurements of YBa2Cu3O7−δ bicrystal grain boundaries

Spatially-resolved nonlinearity measurements of YBa2Cu3O7−δ bicrystal grain boundaries

Surface-barrier effects in the microwave second-harmonic response of superconductors in the mixed state

Time evolution of the microwave second-order response of YBaCuO powder

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Nonlinear magnetization ofYBa2Cu3I. Ciccarello1, Claudio Fazio2, M. Guccione3 et al.

Cited by 28 publications

References 13 publications

Spatially-resolved nonlinearity measurements of YBa2Cu3O7−δ bicrystal grain boundaries

Spatially-resolved nonlinearity measurements of YBa2Cu3O7−δ bicrystal grain boundaries

Surface-barrier effects in the microwave second-harmonic response of superconductors in the mixed state

Time evolution of the microwave second-order response of YBaCuO powder

Contact Info

Product

Resources

About

Nonlinear magnetization ofYBa2Cu3
I. Ciccarello
¹
,
Claudio Fazio
²
,
M. Guccione
³

et al.