Observation of infinite-range intensity correlations above, at and below the 3D Anderson localization transition

TL;DR

This study experimentally observes and analyzes long-range intensity correlations, including the infinite-range C0 contribution, across the 3D Anderson localization transition in disordered materials, revealing their enhancement near mobility edges.

Contribution

It provides the first experimental detection of the infinite-range C0 correlation contribution in 3D Anderson localization, linking it to the critical regime via the anomalous dimension.

Findings

C0 correlations are significantly enhanced near mobility edges.

C0 correlations are linked to the anomalous dimension .

Experimental evidence supports the role of C0 in Anderson transition criticality.

Abstract

We investigate long-range intensity correlations on both sides of the Anderson transition of classical waves in a three-dimensional (3D) disordered material. Our ultrasonic experiments are designed to unambiguously detect a recently predicted infinite-range C0 contribution, due to local density of states fluctuations near the source. We find that these C0 correlations, in addition to C2 and C3 contributions, are significantly enhanced near mobility edges. Separate measurements of the inverse participation ratio reveal a link between C0 and the anomalous dimension \Delta_2, implying that C0 may also be used to explore the critical regime of the Anderson transition.