Anderson localization of matterwaves in optical speckle

In 1958, P.W. Anderson predicted the exponential localization of electronic wave functions in disordered solids, and the resulting absence of diffusion. It has been realized later that Anderson localization is ubiquitous in wave physics as it originates from the interference between multiple scattering paths, and this has prompted an intense activity to observe it with light waves, microwaves, sound waves, and electron gases, but there was no direct observation of exponential spatial localization of matterwaves (electrons or others).