Critical magnetic field of the vortex-free state in NbC thin films and prospects for its observation in MgB2

The flux creep phenomena and the J c characteristics have been investigated in the YBa 2 Cu 3 O 7 (YBCO) thin films grown by metal organics chemical vapor deposition (MOCVD) technique. The anisotropy of the current density (J c ) is discussed on the basis of the intrinsic pinning model and the anisotropic critical magnetic field (H c2 ). The properties of the high J c and the pinning energy are related with the fine precipitates observed by tunneling electron microscopy (TEM). The strong pinning mechanism affects the amount of the flux motion.

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Upper critical magnetic field and vortex-free state in very thin epitaxial δ-MoN films grown by polymer-assisted deposition

Superconductor Science and Technology ◽

10.1088/0953-2048/26/10/105023 ◽

2013 ◽

Vol 26 (10) ◽

pp. 105023 ◽

Cited By ~ 14

Author(s):

N Haberkorn ◽

Y Y Zhang ◽

Jeehoon Kim ◽

Thomas M McCleskey ◽

Anthony K Burrell ◽

...

Keyword(s):

Magnetic Field ◽

Critical Magnetic Field ◽

Free State ◽

Upper Critical Magnetic Field

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Critical magnetic field of V<inf>3</inf>Ga thin films with third element additions

IEEE Transactions on Magnetics ◽

10.1109/tmag.1985.1063634 ◽

1985 ◽

Vol 21 (2) ◽

pp. 1144-1146 ◽

Cited By ~ 6

Author(s):

P. Tedrow ◽

J. Tkaczyk ◽

R. Meservey ◽

S. Bending ◽

R. Hammond

Keyword(s):

Magnetic Field ◽

Thin Films ◽

Critical Magnetic Field

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Effect of interface pinning on dissipation, volume pinning force and measurement of upper critical magnetic field in MgB2 thin films

Physica C Superconductivity ◽

10.1016/s0921-4534(02)02358-4 ◽

2003 ◽

Vol 385 (3) ◽

pp. 313-321 ◽

Cited By ~ 8

Author(s):

S.K Gupta ◽

Shashwati Sen ◽

Niraj Joshi ◽

D.K Aswal ◽

I.K Gopalakrishnan ◽

...

Keyword(s):

Magnetic Field ◽

Thin Films ◽

Critical Magnetic Field ◽

Pinning Force ◽

Upper Critical Magnetic Field ◽

Mgb2 Thin Films

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Quantum Griffiths singularities in TiO superconducting thin films with insulating normal states

NPG Asia Materials ◽

10.1038/s41427-019-0181-3 ◽

2019 ◽

Vol 11 (1) ◽

Cited By ~ 4

Author(s):

Chao Zhang ◽

Yunjie Fan ◽

Qiaoling Chen ◽

Tianyi Wang ◽

Xiang Liu ◽

...

Keyword(s):

Magnetic Field ◽

Thin Films ◽

Critical Exponent ◽

Direct Evidence ◽

Critical Magnetic Field ◽

Josephson Coupling ◽

Superconducting Thin Films ◽

Normal States ◽

Rare Regions ◽

The Magnetic Field

AbstractA superconductor–metal transition (SMT) with an unconventional diverging dynamic critical exponent was recently discovered, and it drew tremendous attention because this signature of a quantum Griffiths singularity (QGS) was thought to be a common characteristic of low-disorder crystalline superconductors. However, because the QGS was observed only in limited materials with metallic normal states, the question of whether the QGS exists in other superconducting systems is still unanswered. In this paper, a superconductor–insulator transition (SIT) is observed in TiO thin films with insulating normal states, which offers a more universal platform for investigating the QGS. A thickness-tuned SIT is obtained when the magnetic field is zero. Importantly, a magnetic field-tuned SIT with a diverging dynamic critical exponent, which is direct evidence of a QGS, is observed in TiO thin films with different thicknesses. By constructing a comprehensive phase diagram, it is demonstrated that the critical magnetic field Hc tends to saturate as the temperature approaches 0 K, which is different from the upturn trend of Hc observed in SMT systems and probably due to the weaker Josephson coupling of the locally ordered superconducting islands (rare regions) in a weakly insulating normal state background. The results extend the QGS scenario from only SMT systems to SIT systems, and they provide vital evidence that QGSs are common in crystalline superconducting thin films, which has possible applications in quantum-computing devices.

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