www.nsf.gov
What are quantum networks?
Today's internet moves information between devices using bits, units of data that exist in one of two states: 0 or 1. Quantum networks are designed to move a different kind of information: quantum information. Instead of bits, quantum devices use quantum bits, or "qubits," which behave according to the rules of quantum mechanics.
Unlike ordinary bits, qubits have the seemingly impossible (but real) ability to simultaneously be in state 0, state 1 and a combination of both — a phenomenon known as superposition. Qubits can also be linked to one another through another quantum phenomenon called entanglement, where changes to one qubit instantaneously affect the others, even across long distances.