2D Coulomb glass as a model of strong vortex pinning in thin-film superconductors

TKM Institutsseminar

Vortragender:

Igor Poboiko

Datum:

05.05.2022 12:30

Ort:

Room 10.01, Bldg. 30.23, Campus South and via Zoom

Zugehörigkeit:

tba

Gastgeber:

Prof. Dr. Alexander Mirlin

Abstract

A glass model of vortex pinning in highly disordered thin superconducting films in magnetic fields B << H_{c2} at low temperatures is proposed. Strong collective pinning of a vortex system realized in disordered superconductors that are close to the quantum phase transition to the insulating phase — such as InO_x, NbN, TiN, MoGe, nano-granular aluminium, and others — is considered theoretically for the first time. Utilizing the replica trick developed for the spin glass theory, we demonstrate that such vortex system is in non-ergodic state of glass type with large kinetic inductance per square L_K. Distribution function of local pinning energies is calculated, and it is shown that it possesses a wide gap, i.e. the probability to find a weakly pinned vortex is extremely low.