**Controlling transport and localization in a disordered Floquet system**

Anderson localization, which has long been a paradigm of condensed matter physics, has been observed and studied in the last decades in many different disordered systems, both classical and quantum. The symmetry characteristics of the disordered system are expected to greatly affect its localization and transport properties. Here we report upon the experimental realization of an artificial gauge field in a synthetic (temporal) dimension of a disordered, periodically driven (Floquet) quantum system.
Our technique is used to control the Time-Reversal Symmetry (TRS) properties, and leads to two experimental observations representing ‘smoking-gun’ signatures of this symmetry breaking. The first consists in the first observation of the “Coherent Forward Scat-
tering” (CFS), a novel genuine interferential signature of the onset of the (strong) Anderson localization. The second is a measurement of the β(g) function, with a direct test of the one-parameter scaling hypothesis, and its universality in two different symmetry classes.