A phase battery for quantum technologies
Batteries belongs to everyday life. A classical battery, the Volta's pile, converts chemical energy into a voltage, which can power electronic circuits. In many quantum technologies, circuits or devices are based on superconducting materials. In such materials, currents may flow without the need of an applied voltage; therefore, there is no need for a classical battery in such a system. These currents are called supercurrents because they do not exhibit any energy losses. They are induced not from a voltage but from a phase difference of the wave function of the quantum circuit, which is directly related to the wave nature of matter. A quantum device able to provide a persistent phase difference can be seen as a quantum phase battery, which induces supercurrents in a quantum circuit.