# Direct measurement of superdiffusive and subdiffusive energy transport in disordered granular chains

## TL;DR

This paper presents the first experimental investigation of energy transport in disordered nonlinear granular chains, showing how disorder and nonlinearity can counteract localization and tune energy transport from subdiffusive to superdiffusive regimes.

## Contribution

It provides the first systematic experimental analysis of how disorder and nonlinearity interact to influence energy transport and localization in granular crystals.

## Key findings

- Disorder and nonlinearity can cancel each other's localization effects.
- Energy transport can be manipulated from subdiffusive to superdiffusive.
- Experimental evidence of combined effects on energy localization and transport speed.

## Abstract

The study of energy transport properties in heterogeneous materials has attracted scientific interest for more than a century, and it continues to offer fundamental and rich questions. One of the unanswered challenges is to extend Anderson theory for uncorrelated and fully disordered lattices in condensed-matter systems to physical settings in which additional effects compete with disorder. Specifically, the effect of strong nonlinearity has been largely unexplored experimentally, partly due to the paucity of testbeds that can combine the effect of disorder and nonlinearity in a controllable manner. Here we present the first systematic experimental study of energy transport and localization properties in simultaneously disordered and nonlinear granular crystals. We demonstrate experimentally that disorder and nonlinearity --- which are known from decades of studies to individually favor energy localization --- can in some sense "cancel each other out", resulting in the destruction of wave localization. We also report that the combined effect of disorder and nonlinearity can enable the manipulation of energy transport speed in granular crystals from subdiffusive to superdiffusive ranges.