There are numerous quantum computers, and right now, they generally only exist for the purpose of scientific research, and they are not found anywhere but a lab. The quantum computers that do exist have been employed using optics, superconducting qubits, semiconductors, NMR, and ion traps. They are not practical, but they do operate at a much different rate than the classic computer.
IBM, Google, and Microsoft are creating their own, while places such as The United States and Chinese governments are all investing in the equipment. There are a few quantum computers which are available to people. They are built by a company called D-Wave, and they cost $15 billion. It is debatable, however, whether they are “quantum driven” computers.