Bulk superinsulation and polar nematic order in nanopatterned NbTiN

TL;DR

This paper reports the experimental discovery of 3D superinsulation and polar nematic order in nanopatterned NbTiN, demonstrating that superinsulation can occur in ordered structures due to electric confinement, not just disorder.

Contribution

It provides the first experimental evidence of superinsulation in ordered nanopatterned structures and links it to electric confinement rather than disorder.

Findings

Observation of Vogel-Fulcher-Tamman scaling of conductance near critical temperature

Vanishing conductance below the transition temperature

Detection of polar nematic order from ferroelectric alignment

Abstract

We present an experimental evidence of 3D superinsulation in a nanopatterned slab of NbTiN, given by the Vogel-Fulcher-Tamman (VFT) scaling of the conductance when approaching the critical temperature from above and by the vanishing of the conductance below the transition. In the electric Meissner state, we find polar nematic order arising from ferroelectric alignement of short electric strings excited by external electromagnetic fields. Our results prove that superinsulation appears also in ordered structures provided that these are large enough, thereby confirming the origin of superinsulation as electric confinement, independent of disorder.