Quantum memory cell using broadband superconducting tunable resonator

A method, comprising:

• obtaining, by a system comprising at least one processor, quantum information;
• obtaining, by the system, a write signal;
• in response to the write signal, performing, by the system, a write operation to a quantum memory cell, comprising matching a first resonance frequency of a superconducting resonator of the quantum memory cell associated with the quantum information, to a second resonance frequency of a quantum storage cavity of the quantum memory cell, to transfer quantum energy corresponding to the quantum information from the superconducting resonator to the quantum storage cavity, and
• after completion of the write operation, unmatching, by the system, the first resonance frequency of the superconducting resonator from the second resonance frequency of the quantum storage cavity to prevent transfer of the quantum energy from the quantum storage cavity back to the tunable superconducting resonator.

A quantum memory cell, comprising:

• a quantum storage cavity comprising a resonator having a first resonance frequency;
• and
• a superconducting tunable resonator device, comprising:
• a superconducting transmission line coupled to a signal input port, a superconducting inductor, and a capacitor, and
• a tuning device that tunes a resonant frequency of the superconducting tunable resonator device, the tuning device comprising:
• one or more radio frequency-superconducting quantum interference devices (rf-SQUIDs) inductively coupled to the superconducting transmission line, and
• a control wire inductively coupled to the one or more rf-SQUIDS, wherein a direct current applied to the control wire flows through the control wire as a control current that determines an inductance of the one or more rf-SQUIDs to tune the resonant frequency of the superconducting tunable resonator device;
• wherein, at a write time, the control current comprises a first control current that tunes the resonant frequency of the superconducting tunable resonator device to the first resonance frequency, to transfer quantum energy on the superconducting transmission line of the superconducting resonator to the quantum storage cavity,
• wherein, at a storage time, the control current comprises a second control current that tunes the resonant frequency of the superconducting tunable resonator device to a second resonance frequency that is different from the first resonance frequency, to prevent transfer of the quantum energy back from the quantum storage cavity to the superconducting transmission line, and
• wherein, at a read time, the control current comprises the first control current that tunes the resonant frequency of the superconducting tunable resonator device to the first resonance frequency, to transfer the quantum energy back from the quantum storage cavity to the superconducting transmission line of the superconducting resonator.