Quantum computers are machines that harness the properties of quantum states, such as superposition, interference, and entanglement, to perform computations. In a quantum computer, the basic unit of memory is a quantum bit, or qubit, which can only be detected at extremely low energy levels and at temperatures close to absolute zero. A quantum computer with enough qubits has a computational power inaccessible to a classical computer, which is referred to as “quantum advantage”.

Superconducting qubits are one of the most promising candidates for developing commercial quantum computers. Indeed, superconducting qubits can be fabricated using standard microfabrication techniques. Moreover, they operate in the few GHz bandwidth such that conventional microwave electronic technologies can be used to control qubits and readout the quantum states.

The operation of a universal quantum computer is based on quantum gates that, just like the logic gates of a classical computer, perform basic operations. By programming these operations in a sequence, it is possible to implement any arbitrary complex algorithm.