Systems and methods for achieving orthogonal control of non-orthogonal qubit parameters

A method of controlling qubit parameters in a quantum processor, wherein the quantum processor includes a plurality of qubits, each qubit having a respective first programmable parameter and a respective second programmable parameter that at least partially depends on the respective first programmable parameter, and a plurality of coupling devices that each selectively provide communicative coupling between respective pairs of the qubits, the method comprising:

• communicatively coupling at least three of the qubits to one another as a single logical qubit, the single logical qubit formed by a first outermost qubit, a second outermost qubit and at least one intermediary qubit, the at least one intermediary qubit strongly communicatively coupled between the first and the second outermost qubits, the first outmost qubit being an outermost qubit of the qubits of the logical qubit in a first direction along a logical qubit path defined by the qubits of the logical qubit and the second outermost qubit being an outermost qubit in a second direction along the logical qubit path;
• for at least one of the at least one intermediate qubits of the logical qubit, communicatively coupling an orthogonal control qubit to the respective intermediate qubit such that the orthogonal control qubit is not communicatively coupled to any other qubit except via the respective intermediate qubit;
• programming the first and the second outermost qubits to have respective first programmable parameters less than or equal to a first value;
• and
• programming the orthogonal control qubit to have a value of the first programmable parameter higher than the first value.

A quantum processor apparatus, comprising:

• a plurality of qubits, each qubit having a respective first programmable parameter and a respective second programmable parameter that at least partially depends on the respective first programmable parameter, and
• a plurality of coupling devices that each selectively provide communicative coupling between respective pairs of the qubits, wherein:
• at least three of the qubits are communicatively coupled to one another as a single logical qubit, the single logical qubit formed by a first outermost qubit, a second outermost qubit and at least one intermediary qubit, the at least one intermediary qubit strongly communicatively coupled between the first and the second outermost qubits, the first outmost qubit being an outermost qubit of the qubits of the logical qubit in a first direction along a logical qubit path defined by the qubits of the logical qubit and the second outermost qubit being an outermost qubit in a second direction along the logical qubit path;
• for at least one of the at least one intermediate qubits of the logical qubit, at least one of the qubits communicatively coupled as an orthogonal control qubit to the respective intermediate qubit such that the orthogonal control qubit is not communicatively coupled to any other qubit except via the respective intermediate qubit;
• the first and the second outermost qubits each have a respective first programmable parameters less than or equal to a first value;
• and
• the orthogonal control qubit has a value of the first programmable parameter higher than the first value.

A method of controlling qubit parameters in a quantum processor, wherein the quantum processor includes a plurality of qubits, each qubit having a respective first programmable parameter and a respective second programmable parameter that at least partially depends on the respective first programmable parameter, and a plurality of coupling devices that each selectively provide communicative coupling between respective pairs of the qubits, the method comprising:

• for at least a first qubit, communicatively coupling an orthogonal control qubit to the first qubit such that the orthogonal control qubit is not communicatively coupled to any other qubit except via the first qubit;
• for at least the first qubit, communicatively coupling the first qubit to at least a second qubit which is not the orthogonal control qubit;
• programming the first qubits to have respective first programmable parameters less than or equal to a first value;
• and
• programming the orthogonal control qubit to have a respective value of the first programmable parameter higher than the first value.

A quantum processor apparatus, comprising:

• a plurality of qubits, each qubit having a respective first programmable parameter and a respective second programmable parameter that at least partially depends on the respective first programmable parameter, and
• a plurality of coupling devices that each selectively provide communicative coupling between respective pairs of the qubits, wherein:
• at least one of the qubits is communicatively coupled as an orthogonal control qubit to a first qubit such that the orthogonal control qubit is not communicatively coupled to any other qubit except via the first qubit;
• the first qubit is communicatively coupled to at least a second qubit which is not the orthogonal control qubit;
• the first qubit has a respective first programmable parameter less than or equal to a first value;
• and
• the orthogonal control qubit has a respective value of the first programmable parameter higher than the first value.