Blocked? No. Greatly attenuated and restricted in what modes can be accommodated? Yes.
More critically though the study gets into how they used a reference wave packet to establish a stationary baseline for the interferometer. Assuming the experiment is sufficiently isolated to reduce noise below the necessary threshold this can work in principle.
> Blocked? No. Greatly attenuated and restricted in what modes can be accommodated? Yes.
Can you give me some examples? I guess I'm thinking lead barriers or a Bose Einstein condensate but curious what you mean here.
Your house has walls to attenuate photons.
Casimir plates are a good example, although Faraday cages are probably better known along with Mu-metal.