Noise Induced Universal Diffusive Transport in Fermionic Chains

Understand

We develop a microscopic transport theory in a randomly driven fermionic model with and without linear potential.

• The operator dynamics arise from the competition between noisy and static couplings, leading to diffusion regardless of ballistic transport or Stark localization in the clean limit.
• The universal diffusive behavior is attributed to a noise-induced bound state arising in the operator equations of motion at small momentum.
• By mapping the noise-averaged operator equation of motion to a one-dimensional non-hermitian hopping model, we analytically solve for the diffusion constant, which scales non-monotonically with noise strength, revealing regions of enhanced and suppressed diffusion from the interplay between onsite and bond dephasing noise, and a linear potential.