We know that two scientists, Takaaki Kajita and Arthur B. McDonald, working on Neutrinos have just been awarded the 2015 Nobel Prize in Physics. My question as a Nobel Prize Challenge Question is: could neutrinos be used for quantum information processing?
Requirements based the DiVincenzomy criteria and my preliminary thoughts:
A neutrino has to be able to serve at least as a qubit. That is to say, at least two fiducial states of neutrinos can be used to represent $|0\rangle$ and $|1\rangle$ states. You can use motional states, spin states or any other neutrino quantum states for the fiducial states. Arbitrary superpositions of those fiducial states and entangled states can be constructed easily. Certainly, you can have more than two fiducial states to form qutrits or qudits.
There must be a way to bring in a robust interaction mechanism between neutrinos, or between neutrinos and other particles. Based on the interaction mechanisms, the neutrino state can be prepared/initialized at least to a uniform state (say all in $|0\rangle$ state).
At least universal single qubit gates and two-qubit gates can be constructed stably to interact with the qubits. For instance, gates like CNOT, Pauli Z (or NOT)/X/Y, T and S (SU(2) rotations with some angles) gates. The processing time per gate must be shorter than the storage time and neutrino's decay time.
To make the system easier to control and to make information storable, it would be nice if neutrino systems are able to exchange information with other local qubit units which can be easily controlled and stored coherently. If this exchange mechanism is hard to satisfy, it will at least require a robust quantum memory protocol for neutrino themselves which has a storage time longer than its decay or life time.
There should be a way to robustly read-in and read-out quantum information as classical information so that human beings can recognize the information processed or to be processed.
A neutrino itself can be a fly qubit, of course. This is required for quantum communication and transporting quantum information, which may be the best thing that people want to use due to the super-weak interaction between neutrinos and other matters. If all the other criteria fail, conditions 2, 5 and 6 themselves can make neutrinos a good candidate for quantum communications for extreme needs.
I am not working on neutrino science, but I would like to see how experts of neutrino science say about whether the criteria above could be satisfied at least in theory. Thanks.