Roles of electron mean free path and flux pinning in optimizing the critical current in YBCO superconductors

Abstract

We present a way to reach the maximum possible critical current density, Jc , for YBa2Cu3O6+x (YBCO) thin films. This value is found to be around ten times the currently reached values. It is found that the Jc}(0 T) is governed by the mean free path of the electrons, as is the critical temperature, Tc . The Jc in field, on the other hand, is governed by flux pinning and can be enhanced by optimizing the size and distribution of the non-superconducting nanoinclusions. By optimizing both the mean free path and the pinning structure, the maximum values can be reached

Quantifying Nonadiabaticity in Major Families of Superconductors

“…The remarkable agreement of the deduced value, , and the value reported in the original work on MATBG by Cao et al [ 95 ], , which was calculated based on normal state charge carriers density in MATBG, independently validates our primary idea [ 84 ] about the fundamental nature of the self-field critical current in weak-links samples [ 84 , 85 , 111 ]. This concept was recently proven by Paturi and Huhtinen [ 112 ], who utilized the fact that the London penetration depth, , in real samples, depends on the mean free-path of charge carriers, : where is the effective penetration depth, and is the penetration depth in samples, exhibiting a very long mean free-path, . Paturi and Huhtinen [ 112 ] varied in YBa 2 Cu 3 O 7-x films and showed that the change in satisfies Equations (18) and (19).…”

“…This concept was recently proven by Paturi and Huhtinen [ 112 ], who utilized the fact that the London penetration depth, , in real samples, depends on the mean free-path of charge carriers, : where is the effective penetration depth, and is the penetration depth in samples, exhibiting a very long mean free-path, . Paturi and Huhtinen [ 112 ] varied in YBa 2 Cu 3 O 7-x films and showed that the change in satisfies Equations (18) and (19).…”

Defining optimal thickness for maximal self-field Jc in YBCO/CeO2 multilayers grown on buffered metal

“…High-temperature superconductor YBa 2 Cu 3 O 6+x (YBCO) thin films and coated conductors hold great potential for a variety of power applications, energy storage, high-speed computing etc [1][2][3][4][5], but to realize their full capability, the overall critical current density (J c ) needs to be maximized [6,7]. Since the thermal excitation of Cooper pairs and the field strength dependent Meissner effect greatly affect the J c , it is essential to design specific structures for various applications operating at different temperatures and magnetic fields.…”

Improved Crystalline Quality and Self-Field $J_{\mathrm{c}}$ in Sequentially Vacuum-Multilayered YBCO Thin Films on Buffered Metallic Templates

“…T O maximize the absolute critical current density J c of YBCO thin films and coated conductors at high magnetic fields favourable for electric power applications [1]- [7], requirements of both the high crystalline quality and optimal flux pinning properties should be fulfilled [8]- [10]. The flux pinning structure organized with an artificially produced nanocolumn network within the YBCO matrix that maximally pins the vortices is widely studied [11]- [17], but the formation of crystalline defects that directly affect the shortening of the electron mean free path and thus the zero-field critical current density has got less attention in the field of hightemperature superconductors [9], [18]- [21]. In the zero-and low-field applications below ≈100 mT, the crystalline structure of YBCO is solely responsible for maximum J c and in the mid-field applications between 100 mT and ≈2 T, the J c at the zero-field unambiguously limits the in-field properties [10].…”