YBa2Cu3O7 as a high-temperature superinductor

Abstract

The magnetic behaviour of type-II superconductors is explained by a quantum vortex with a supercurrent encircling a coherence-length-sized core. In a superconducting film with a thickness of t < λL, the vortex field decays slowly as 1/r2, extending to the Pearl length $${P}_{{\rm{L}}}=\frac{2{\lambda }_{{\rm{L}}}^{2}}{t}$$ , known as the Pearl vortex, rather than diverging as log[1/r] and decaying with London penetration depth λL, as that in the Abrikosov vortex. However, the effect of the Pearl vortex on a large enhancement in the kinetic inductance has not been fully explored. Here we discovered Pearl inductance, an additional form of kinetic inductance arising from geometrical structuring of high-superconducting-transition-temperature (Tc) YBCO superconductor thin films at the Pearl length scale. This results from an extension of vortex screening supercurrents from λL to 14λL in an ultrathin metamaterial resonator of thickness λL/7, enabling terahertz superinductance. Our device shows impedance exceeding the quantum resistance limit RQ = 6.47 kΩ by 33%, offering possibilities for cutting-edge electronic, photonic and quantum devices. Pearl inductance in thin films of YBCO enables terahertz superinductance and achieves impedance surpassing the quantum resistance limit, promising advancements in quantum and photonic technologies.