Researchers have explored information transfer in many-body quantum systems, a crucial aspect for quantum communication and state transfer. The study focuses on a one-dimensional open chain of qudits, aiming to retrieve information encoded at one end by measurements at the opposite end. By restricting the dynamics to brickwork quantum circuits and considering M-qudit subsystems within the causal "light cone" of the circuit, they have obtained results applicable to large systems (N) or non-integrable global dynamics.

The key to the research lies in linking lossless information transfer to the existence of peripheral eigenvalues of a quantum channel, Φ_M, which describes the evolution of the local M-qudit subsystem along the light cone. The conditions under which brickwork circuits exhibit these peripheral eigenvalues have been investigated. For qubit chains with M=1, the dual-unitary property is a necessary condition, whereas for larger local subsystems (M ≥ 2) or higher-dimensional qudits, this requirement may be less strict.

Surprisingly, the peripheral eigenvalue condition has allowed for the construction of examples of lossless information transfer across chains of arbitrary size N. This is possible even when the underlying circuit dynamics are non-integrable and exhibit thermalization at long times. These findings open new avenues for understanding and designing robust quantum systems for information transmission, overcoming the limitations imposed by the complexity of many-body dynamics.