(Phys.org)—It might be said that the most difficult part of building a quantum computer is not figuring out how to compose it compute,but rather finding a way to deal with all of the errors that it inevitably makes. Errors arise because of the fixed interaction between the qubits and their environment, which can result in photon loss, and which in turn causes the qubits to randomly flip to an incorrect state.
Source: phys.org