Magic state factory constructions for producing CCZ and T states
AssigneeGoogle Inc.
InventorsCraig Gidney, Austin Greig Fowler
Life of this patent
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Abstract
Methods, systems, and apparatus for producing CCZ states and T states. In one aspect, a method for transforming a CCZ state into three T states includes obtaining a first target qubit, a second target qubit and a third target qubit in a CCZ state; performing a X−1/2 gate on the third target qubit; performing an X gate on the first target qubit and the second target qubit using the third target qubit as a control; performing a Z gate on the first target qubit and the second target qubit using the third qubit as a X axis control; performing a Z−1/4 gate on the third target qubit; and performing a Z gate on the first target qubit and the second target qubit using the third qubit as a X axis control to obtain the three T states.
Claims20
A method for transforming a CCZ state into three output T states, the method comprising:
- obtaining three target qubits prepared in a CCZ state;
- performing an X gate on a target qubit using a first stabilizer qubit as a control and measuring the first stabilizer qubit to determine a state of the first stabilizer qubit;
- performing an X gate on multiple target qubits using a second stabilizer qubit as a control and measuring the second stabilizer qubit to determine a state of the second stabilizer qubit;
- performing a Z gate on multiple target qubits using a third stabilizer qubit as a control;
- performing a Z gate on a target qubit using a fourth stabilizer qubit as a control;
- performing a Z gate on multiple target qubits using two stabilizer qubits of the first, second, third or fourth stabilizer qubits as a control;
- and
- performing multiple classically controlled Pauli operators on the three target qubits conditioned on states of multiple ancilla qubits.
A quantum computing device comprising:
- a register of qubits comprising multiple target qubits, multiple ancilla qubits, and multiple stabilizer qubits each prepared in a respective initial state;
- a plurality of control lines coupled to the register of qubits;
- a plurality of control devices coupled to the plurality of control lines;
- and
- one or more classical processors;
- wherein the quantum computing device is configured to perform classical and quantum operations for transforming a CCZ state into three output T states, the operations comprising:
- obtaining three target qubits prepared in a CCZ state;
- performing an X gate on a target qubit using a first stabilizer qubit as a control and measuring the first stabilizer qubit to determine a state of the first stabilizer qubit;
- performing an X gate on multiple target qubits using a second stabilizer qubit as a control and measuring the second stabilizer qubit to determine a state of the second stabilizer qubit;
- performing a Z gate on multiple target qubits using a third stabilizer qubit as a control;
- performing a Z gate on a target qubit using a fourth stabilizer qubit as a control;
- performing a Z gate on multiple target qubits using two stabilizer qubits of the first, second, third, or fourth stabilizer qubits as a control;
- and
- performing multiple classically controlled Pauli operators on the three target qubits conditioned on states of multiple ancilla qubits.
Dependencies are inferred from the claim text.