What does "qubit" mean in quantum computer terminology?
Qubits – quantum bits – are the same elementary blocks of a quantum processor as transistors in the processors of conventional computers. It is necessary to distinguish between the theoretical concept of a qubit, as a unit of quantum information, and the physical embodiment of qubits, for which various physical systems can be used – photons, ions, spins of nuclei and electrons. Today, most hopes are placed on superconducting qubits.
But how does a qubit work? We are all familiar with bits – zeros and ones, which are processed by conventional computers. Quantum bits are very similar (although not without quantum oddities). They also have two basic states – 0 and 1, but, thanks to a special quantum property – superposition – they can be in any of the states between zero and one.