Anomalous Hall effect in superconductors near their critical temperatures

Hagen, S. J.; Lobb, C. J.; Greene, R. L.; Forrester, M. G.; Kang, Joonhee

doi:10.1103/physrevb.41.11630

Cited by 218 publications

(129 citation statements)

References 13 publications

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“…[22][23][24][25][26][27] Although sign reversal of ρ xy has been observed, its origin remains controversial. [28][29][30] Vinokur et al [31] considered the momentum balance and proposed a model where a system of interacting vortices under quenched disorders and thermal noises follows a universal scaling law with a universal β = 2.0. However, this model does not explain all the mixed-state Hall effects of high-T c superconductors.…”

Section: Introductionmentioning

confidence: 99%

Anomalous scaling behavior in a mixed-state Hall effect of a cobalt-doped BaFe2As2epitaxial film with a high critical current density over 1 MA/cm
Sato
¹
,
Katase
²
,
Kang
³

et al. 2013
Phys. Rev. B
17
1
7
0
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The mixed-state Hall effect was examined in a Ba(Fe 1-x Co x ) 2 As 2 epitaxial film with a high critical current density. The transverse resistivity ρ xy and the longitudinal resistivity ρ xx follow power law scaling ρ xy = Aρ xx β . In the temperature-sweep with a fixed field (T sweep), all of the β values are independent of magnetic field up to 9 T, and are lower than 2.0 (around 1.8). In contrast, the β values in the magnetic-field sweep with a fixed temperature (H sweep) change from 1.8 to 2.0 as the temperature increases from 13 to 16 K even in the T/H region that overlaps with the T sweep measurements. These results indicate that the vortices introduced at low temperatures are trapped by strong pinning centers, but a portion of the vortices introduced at high temperatures are not strongly trapped by the pinning centers. The sign of ρ xy is negative, and a sign reversal is not detected. These distinct scaling behaviors, which sharply contrast cuprates and MgB 2 , are explained by high-density c-axis pinning centers in the Ba(Fe 1-x Co x ) 2 As 2 epitaxial film and are consistent with a wider vortex liquid phase. H. Sato et al. 3

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Section: Introductionmentioning

confidence: 99%

Anomalous scaling behavior in a mixed-state Hall effect of a cobalt-doped BaFe2As2epitaxial film with a high critical current density over 1 MA/cm
Sato
¹
,
Katase
²
,
Kang
³

et al. 2013
Phys. Rev. B
17
1
7
0
View full text Add to dashboard Cite

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mentioning

confidence: 99%

mentioning

confidence: 99%

“…[11,12] In the mixed-state, the flux-flow Hall effect is also quite interesting. A puzzling sign anomaly has been observed in some conventional superconductors [13,14] as well as in most of high-T c superconductors.[15] Even double [16,17] or triple sign changes [15] have been observed in some high-T c superconductors. Furthermore, a universal scaling behavior between the Hall resistivity and the longitudinal resistivity has attracted much experimental [15][16][17][18] and theoretical interest.…”

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confidence: 99%

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Hole carrier in MgB2 characterized by Hall measurements

Kang

Jung

Kim

et al. 2001

Applied Physics Letters

104

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The longitudinal resistivity ρxx and Hall coefficient RH were measured for MgB2 sintered under high pressure. We found that RH is positive like cuprate high-Tc superconductors, and decreases as temperature increases for 40 K < T < 300 K. The cotangent of Hall angle was found to follow a + bT 2 behavior from Tc to 300 K. At T = 100 K, RH = 4.1 × 10 −11 m 3 /C from which hole carrier density was determined to be 1.5 × 10 23 /cm 3 . This carrier density is 2 -3 orders of magnitude larger than those of Nb3Sn and optimally doped YBa2Cu3Oy superconductors.Recently, MgB 2 was found to be metallic superconductor with transition temperature (T c ) of about 40 K. [1,2], and has provided great scientific interest. Several thermodynamic parameters have been estimated, [3,4] such as a upper critical field H c2 = 13 -18 T, a GinzburgLandau parameter κ ∼ 26, and the critical supercurrent density J c (0) ∼ 10 5 A/cm 2 . In order to probe the nature of gap, tunneling spectroscopy measurements have been reported [5,6], and they observed superconducting energy gap (∆) of 5 -7 meV in the framework of the BCS model. The conventional BCS electron-phonon interaction was proposed as the origin of the superconductivity based on a band calculation. [7] The possible origin of the enhanced T c is suggested to originate from a strong electron-phonon interaction and a enhanced phonon frequency due to the light boron mass in MgB 2 . Most of the charge carrier density at the Fermi level comes from the boron band. Indeed, the boron isotope effect has been reported with an exponent of α B ∼ 0.26. [8] No experimental study on the electronic structure has been reported yet.Another interesting feature concerning the normalstate Hall effect in high-T c cuprates is the universal temperature dependence of the cotangent of the Hall angle (cotθ H ). Anderson [10] and Chien et al. [9] have proposed that the charge transport is governed by two different scattering times with different temperature dependences. In this model, the cotθ H should be proportional to T 2 since the Hall angle is proportional to the inverse of the Hall scattering time τ H (∝ T −2 ), and has been observed for most high-T c superconductors. [11,12] In the mixed-state, the flux-flow Hall effect is also quite interesting. A puzzling sign anomaly has been observed in some conventional superconductors [13,14] as well as in most of high-T c superconductors.[15] Even double [16,17] or triple sign changes [15] have been observed in some high-T c superconductors. Furthermore, a universal scaling behavior between the Hall resistivity and the longitudinal resistivity has attracted much experimental [15][16][17][18] and theoretical interest. [19] However, these Hall effects in the mixed state are not well understood.To understand the superconductivity in MgB 2 , it is essential to know the type of charge carrier and it's density, but these have not been reported yet . Theoretically, Hirsch [20] proposed that the 40 K superconductivity of MgB 2 originates mainly from the hole carriers with bor...

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“…This maximum, together with the sign inversion ͑−R H,ref is negative for T Ͼ T c,on ͒, is a clear indication for the existence of the anomalous Hall effect ͑AHE͒, which is common to superconducting systems. [8][9][10] The AHE is caused by vortex motion with a directional component antiparallel to the current direction. 11 Close to T c and in the superconducting regime, vortices are mobile.…”

Section: Resultsmentioning

confidence: 99%

Quantitative analysis of the guidance of vortices in superconducting films with magnetic dots

González

Hollmann

Wördenweber

2007

Journal of Applied Physics

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The guidance of vortices in superconducting Nb films with periodic arrangements of magnetic Ni dots is studied via simultaneous four-probe measurements in standard and Hall configuration. Ni dots are fabricated via e-beam lithography and lift-off technology. Arrays with periodicity down to 400 nm and dot size of 200 nm are obtained. Subsequently, the arrays are covered with a thin superconducting Nb layer. Simultaneous Hall and standard resistive measurements of the flux dynamic in Nb bridges with and without magnetic dots demonstrate and quantify the guidance of flux via the magnetic dots. Guidance of vortices is only possible in a limited current regime; guidance improves with decreasing temperature. Within the identified current regime most of the vortices ͑Ͼ40% for zero field͒ and in the optimum case all of the vortices are guided by the magnetic dots.

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Anomalous Hall effect in superconductors near their critical temperatures

Cited by 218 publications

References 13 publications

Anomalous scaling behavior in a mixed-state Hall effect of a cobalt-doped BaFe2As2epitaxial film with a high critical current density over 1 MA/cm
Sato
¹
,
Katase
²
,
Kang
³

et al. 2013
Phys. Rev. B
17
1
7
0
View full text Add to dashboard Cite

Anomalous scaling behavior in a mixed-state Hall effect of a cobalt-doped BaFe2As2epitaxial film with a high critical current density over 1 MA/cm
Sato
¹
,
Katase
²
,
Kang
³

et al. 2013
Phys. Rev. B
17
1
7
0
View full text Add to dashboard Cite

Hole carrier in MgB2 characterized by Hall measurements

Quantitative analysis of the guidance of vortices in superconducting films with magnetic dots

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Anomalous Hall effect in superconductors near their critical temperatures

Cited by 218 publications

References 13 publications

Anomalous scaling behavior in a mixed-state Hall effect of a cobalt-doped BaFe2As2epitaxial film with a high critical current density over 1 MA/cmSato1, Katase2, Kang3 et al. 2013Phys. Rev. B17170View full textAdd to dashboardCite

Anomalous scaling behavior in a mixed-state Hall effect of a cobalt-doped BaFe2As2epitaxial film with a high critical current density over 1 MA/cmSato1, Katase2, Kang3 et al. 2013Phys. Rev. B17170View full textAdd to dashboardCite

Hole carrier in MgB2 characterized by Hall measurements

Quantitative analysis of the guidance of vortices in superconducting films with magnetic dots

Contact Info

Product

Resources

About

Anomalous scaling behavior in a mixed-state Hall effect of a cobalt-doped BaFe2As2epitaxial film with a high critical current density over 1 MA/cm
Sato
¹
,
Katase
²
,
Kang
³

et al. 2013
Phys. Rev. B
17
1
7
0
View full text Add to dashboard Cite

Anomalous scaling behavior in a mixed-state Hall effect of a cobalt-doped BaFe2As2epitaxial film with a high critical current density over 1 MA/cm
Sato
¹
,
Katase
²
,
Kang
³

et al. 2013
Phys. Rev. B
17
1
7
0
View full text Add to dashboard Cite