Can a neutrino antenna be made one day? I am wondering if it is theoretically possible that some kind of device/material could absorb neutrinos much better than everyday materials (preferably non-thermal absorption). This could enable a sort of neutrino antenna.
 A: How does an electromagnetic antenna work at the photon, quantum mechanical level? By inducing varying electric fields  which induce accelerated charges which radiate coherently  photons which build the classical electromagnetic wave.
The neutrino interacts with the weak interaction , is a fermion and can in no way be in a way similar to a photon, so cannot be regimented as the photon can.
The neutrino is produced in weak interactions, beta decays naturally, and in interactions in accelerators and cosmic rays. Let us see whether a neutrino beam that could be modulated is possible.
As in radioactivity they participate in three body decays there is no way to control their energy and direction so radioactively produced they cannot be coherent in any sense.
This leaves accelerators and cosmic rays. No way to control cosmic ray neutrinos of course. 
If muon beams are produced in accelerators from pion decays, at the same time there will be a neutrino beam from the two body decay. If the production of the muon beam is modulated, the production of neutrinos will be modulated  The problem will be on the detection side, since there are no receiving antennas other than huge detectors, like the OPERA.
What makes neutrinos attractive for gathering signals from the sun and stars, the weak interaction, prohibits any practical uses for the beam.
