Hyperactivated resistance in TiN films on the insulating side of the disorder-driven superconductor-insulator transition

Abstract

We investigate the insulating phase that forms in a titanium nitride film in a close vicinity of the disorder-driven superconductor-insulator transition. In zero magnetic field the temperature dependence of the resistance reveals a sequence of distinct regimes upon decreasing temperature crossing over from logarithmic to activated behavior with the variable-range hopping squeezing in between. In perpendicular magnetic fields below 2 T, the thermally activated regime retains at intermediate temperatures, whereas at ultralow temperatures, the resistance increases faster than that of the thermally activated type. This indicates a change of the mechanism of the conductivity. We find that at higher magnetic fields the thermally activated behavior disappears and the magnetoresistive isotherms saturate towards the value close to quantum resistance h/e^2.

revtex4 file, 6 pages, 4 figures (published)

References in corpus (6)

• Disorder-Induced Inhomogeneities of the Superconducting State Close to the Superconductor-Insulator Transition
• Localized Superconductivity in the Quantum-Critical Region of the Disorder-Driven Superconductor-Insulator Transition in TiN Thin Films
• Quantum Metallicity on the High-Field Side of the Superconductor-Insulator Transition
• Collective transport in the insulating state of Josephson junction arrays
• Scale dependent superconductor-insulator transition
• An inhomogeneous Josephson phase in thin-film and High-Tc superconductors

Cited by in corpus (4)

• Coulomb gap triptychs, $\sqrt{2}$ effective charge, and hopping transport in periodic arrays of superconductor grains
• Overactivated transport in the localized phase of the superconductor-insulator transition
• Gate-tunable electron interaction in high-κ dielectric films
• Proximitized insulators from disordered superconductors