Techniques for generating qubit control signals

A method comprising:

• generating, by a first digital-to-analog converter (DAC) of a first qubit controller, a first time-varying DC current signal based on a first plurality of digital values received by the first DAC;
• receiving, by a first tunable coupling circuit of the first qubit controller, the first time-varying DC current signal;
• generating, by the first tunable coupling circuit, a first baseband pulse sequence component by amplitude-adjusting the first time-varying DC current signal according to a first control signal received by the first tunable coupling circuit, wherein the first control signal is a current signal that generates a DC flux around a superconducting loop of the first tunable coupling circuit;
• generating, by the first qubit controller, a baseband pulse sequence by combining a plurality of baseband pulse sequence components including the first baseband pulse sequence component;
• and
• applying the baseband pulse sequence to a first qubit.

A system comprising:

• a plurality of qubits including a first qubit;
• and
• a plurality of qubit controllers coupled to respective qubits of the plurality of qubits, the plurality of qubit controllers including a first qubit controller configured to apply a baseband pulse sequence to the first qubit, the first qubit controller comprising:
• a first digital memory register;
• a first digital-to-analog converter (DAC) configured to receive a first plurality of digital values from the first digital memory register and generate a first time-varying current signal based on the first plurality of digital values;
• and
• a first tunable coupling circuit coupled to the first DAC and configured to:
• receive the first time-varying current signal from the first DAC;
• and
• generate a first component of the baseband pulse sequence by amplitude-adjusting the first time-varying current signal according to a first control signal received by the first tunable coupling circuit.

A method comprising:

• generating, by a first digital-to-analog converter (DAC) of a first qubit controller, a first time-varying DC current signal based on a first plurality of digital values received by the first DAC;
• receiving, by a first tunable coupling circuit of the first qubit controller, the first time-varying DC current signal;
• generating, by the first tunable coupling circuit, a first baseband pulse sequence component by amplitude-adjusting the first time-varying DC current signal according to a first control signal received by the first tunable coupling circuit;
• generating, by the first qubit controller, a baseband pulse sequence by combining a plurality of baseband pulse sequence components including the first baseband pulse sequence component;
• applying the baseband pulse sequence to a first qubit;
• and
• subsequent to applying the baseband pulse sequence to the first qubit, applying, by the first qubit controller, a second baseband pulse sequence, different from the baseband pulse sequence, to the first qubit.