Simultaneously driving adjacent qubit pairs

A method comprising:

• directing, in a system comprising a first cross-resonance (CR) gate having a first control qubit and a first target qubit and a second CR gate having a second control qubit and a second target qubit, simultaneous CR pulses to the first and second control qubits during first, third, fifth, and seventh time periods,
• wherein the first control qubit is coupled with the first target qubit,
• wherein the second control qubit is coupled with the second target qubit and the first control qubit,
• wherein, during the first and third time periods, the CR pulses to the first control qubit are in phase with each other and the CR pulses to the second control qubit are out of phase with each other,
• wherein, during the fifth and seventh time periods, the CR pulses to the first control qubit are in phase with each other and the CR pulses to the second control qubit are out of phase with each other;
• and
• directing, following the CR pulses, simultaneous primary pulses to the first control qubit of the first CR gate and the second target qubit of the second CR gate during second and sixth time periods and concurrent secondary pulses to the first target qubit of the first CR gate and the second control qubit of the second CR gate during fourth and eighth time periods.

A computer program product for driving a quantum device, the computer program product comprising one or more computer readable storage media, and program instructions collectively stored on the one or more computer readable storage media, the program instructions executable by controller circuitry to cause the controller circuitry to perform operations comprising:

• directing, in a system comprising a first cross-resonance (CR) gate having a first control qubit and a first target qubit and a second CR gate having a second control qubit and a second target qubit, simultaneous CR pulses to the first and second control qubits during first, third, fifth, and seventh time periods,
• wherein the first control qubit is coupled with the first target qubit,
• wherein the second control qubit is coupled with the second target qubit and the first control qubit,
• wherein, during the first and third time periods, the CR pulses to the first control qubit are in phase with each other and the CR pulses to the second control qubit are out of phase with each other,
• wherein, during the fifth and seventh time periods, the CR pulses to the first control qubit are in phase with each other and the CR pulses to the second control qubit are out of phase with each other;
• and
• directing, following the CR pulses, simultaneous primary pulses to the first control qubit of the first CR gate and the second target qubit of the second CR gate during second and sixth time periods and simultaneous secondary pulses to the first target qubit of the first CR gate and the second control qubit of the second CR gate during fourth and eighth time periods.