# Spontaneous Transport Barriers Quench Turbulent Resistivity in 2D MHD

## TL;DR

This paper uncovers how spontaneous magnetic barriers form in 2D MHD turbulence, quenching resistivity by creating a multi-scale structure that concentrates magnetic energy and induces local bistability, fundamentally altering magnetic transport.

## Contribution

It reveals the physical mechanism behind the quench of turbulent resistivity in 2D MHD, linking barrier formation to inverse cascade and negative resistivity phenomena.

## Key findings

- Magnetic barriers form spontaneously in 2D MHD turbulence.
- Barriers concentrate magnetic energy and quench resistivity.
- Layering and magnetic staircase structures emerge at small scales.

## Abstract

This Letter identifies the physical mechanism for the quench of turbulent resistivity in 2D MHD. Without an imposed, ordered magnetic field, a multi-scale, blob-and-barrier structure of magnetic potential forms spontaneously. Magnetic energy is concentrated in thin, linear barriers, located at the interstices between blobs. The barriers quench the transport and kinematic decay of magnetic energy. The local transport bifurcation underlying barrier formation is linked to the inverse cascade of $\langle A^2\rangle$ and negative resistivity, which induce local bistability. For small scale forcing, spontaneous layering of the magnetic potential occurs, with barriers located at the interstices between layers. This structure is effectively a magnetic staircase.