A system comprising a quantum circuit and classical control devices, wherein the quantum circuit comprises: first and second logical qubits (40; 60), each comprising a Bacon-Shor code block comprising a plurality of superconducting physical qubits (41, 42, 43, 44; 61, 62, 63, 64) coupled in an array, such that a first edge of the array of superconducting physical qubits forming each logical qubit contains superconducting physical qubits (43, 44; 63, 64) each coupled to at least one neighboring superconducting physical qubit (41, 42; 61, 62) along the first edge along an X-axis of the Bloch sphere and a second edge of the array of superconducting physical qubits (41, 43; 61, 63) forming each logical qubit contains superconducting physical qubits each coupled to at least one neighboring superconducting physical qubit (42, 44; 62, 64) along the second edge along a Z- axis of the Bloch sphere; a set of couplers (103, 104) configured to couple the first and second logical qubits (40; 60) along the X-axis of the Bloch sphere, each of the set of couplers coupling a superconducting physical qubit (43; 44) along the second edge of the array of superconducting physical qubits forming the first logical qubit to a corresponding superconducting physical qubit (61; 62) along the second edge of the array of superconducting physical qubits forming the second logical qubit along the X-axis of the Bloch sphere, wherein each coupled superconducting physical qubits (43, 61; 44, 62) are coupled such that it is energetically favorable for the states of the each coupled superconducting physical qubits to assume a specific relationship with respect to the appropriate axis, corresponding to a specific quantum state defined on the Bloch sphere, with a negative coupling making it energetically favorable for the states of the coupled superconducting physical qubits to align in the same direction along the axis, and a positive coupling making it energetically favorable for the states of the coupled superconducting physical qubits to align in different directions along the axis; and wherein the classical control devices are configured to provide a control signal to each of the set of couplers (103, 104), each of the set of couplers (103, 104) being tunable via the classical control, such that a strength of the coupling between the first and second logical qubits along the X-axis of the Bloch sphere is tunable by a flux applied to the coupler by the associated classical control device. first and second logical qubits (40; 60), each comprising a Bacon-Shor code block comprising a plurality of superconducting physical qubits (41, 42, 43, 44; 61, 62, 63, 64) coupled in an array, such that a first edge of the array of superconducting physical qubits forming each logical qubit contains superconducting physical qubits (43, 44; 63, 64) each coupled to at least one neighboring superconducting physical qubit (41, 42; 61, 62) along the first edge along an X-axis of the Bloch sphere and a second edge of the array of superconducting physical qubits (41, 43; 61, 63) forming each logical qubit contains superconducting physical qubits each coupled to at least one neighboring superconducting physical qubit (42, 44; 62, 64) along the second edge along a Z- axis of the Bloch sphere; a set of couplers (103, 104) configured to couple the first and second logical qubits (40; 60) along the X-axis of the Bloch sphere, each of the set of couplers coupling a superconducting physical qubit (43; 44) along the second edge of the array of superconducting physical qubits forming the first logical qubit to a corresponding superconducting physical qubit (61; 62) along the second edge of the array of superconducting physical qubits forming the second logical qubit along the X-axis of the Bloch sphere, wherein each coupled superconducting physical qubits (43, 61; 44, 62) are coupled such that it is energetically favorable for the states of the each coupled superconducting physical qubits to assume a specific relationship with respect to the appropriate axis, corresponding to a specific quantum state defined on the Bloch sphere, with a negative coupling making it energetically favorable for the states of the coupled superconducting physical qubits to align in the same direction along the axis, and a positive coupling making it energetically favorable for the states of the coupled superconducting physical qubits to align in different directions along the axis; and wherein the classical control devices are configured to provide a control signal to each of the set of couplers (103, 104), each of the set of couplers (103, 104) being tunable via the classical control, such that a strength of the coupling between the first and second logical qubits along the X-axis of the Bloch sphere is tunable by a flux applied to the coupler by the associated classical control device.