Scientists at the National Institute of Standards and Technology (NIST) have developed the first “dimmer switch” for a superconducting circuit linking a quantum bit (qubit) and a quantum bus—promising technologies for storing and transporting information in future quantum computers. The NIST switch is a new type of control device that can “tune” interactions between these components and potentially could speed up the development of a practical quantum computer.

Quantum computers, if they can be built, would use the curious rules of quantum mechanics to solve certain problems that are now intractable, such as breaking today’s most widely used data encryption codes, or running simulations of quantum systems that could unlock the secrets of high-temperature superconductors. Unlike many competing systems that store and transport information using the quantum properties of individual atoms, superconducting qubits use a “super flow” of oscillating electrical current to store information in the form of microwave energy. Superconducting quantum devices are fabricated like today’s silicon processor chips and may be easy to manufacture at the large scales needed for computation.