Magnetic field-tuned superconductor/insulator transition in TiN nanostrips

TL;DR

This study investigates how magnetic fields influence the superconductor-insulator transition in disordered TiN nanostrips, revealing quantum phase slips, Josephson junction behavior, and a reentrant insulating phase.

Contribution

It demonstrates that critically disordered TiN nanostrips behave like self-organized Josephson networks and explores magnetic field effects on their quantum phase transitions.

Findings

Quantum phase slips cause resistance saturation at low temperatures.

Narrow TiN nanostrips exhibit Josephson junction-like I-V characteristics.

Magnetic fields induce a reentrant insulating phase with dual I-V characteristics.

Abstract

We have measured the electric transport properties of TiN nanostrips with different widths. At zero magnetic field the temperature dependent resistance R(T) saturates at a finite resistance towards low temperatures, which results from quantum phase slips in the narrower strips. We find that the current-voltage (I-V) characteristics of the narrowest strips are equivalent to those of small Josephson junctions. Applying a transverse magnetic field drives the devices into a reentrant insulating phase, with I-V-characteristics dual to those in the superconducting regime. The results evidence that our critically disordered superconducting nanostrips behave like small self-organized random Josephson networks.