US 11,941,488 B2
Methods and apparatus for performing phase operations
Craig Gidney, Goleta, CA (US)
Assigned to Google LLC, Mountain View, CA (US)
Filed by Google LLC, Mountain View, CA (US)
Filed on Mar. 9, 2023, as Appl. No. 18/181,419.
Application 18/181,419 is a continuation of application No. 16/753,699, granted, now 11,625,637, previously published as PCT/US2019/027640, filed on Apr. 16, 2019.
Claims priority of provisional application 62/658,993, filed on Apr. 17, 2018.
Prior Publication US 2023/0297864 A1, Sep. 21, 2023
Int. Cl. G06N 10/20 (2022.01); G06N 10/40 (2022.01); H03K 19/20 (2006.01)
CPC G06N 10/20 (2022.01) [G06N 10/40 (2022.01); H03K 19/20 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A method, performed by a quantum computing device, for duplicating a phased plus state, the method comprising:
performing a phase operation on a first qubit included in the quantum computing device and a second qubit included in the quantum computing device, wherein the first qubit is prepared in an arbitrary initial state and the second qubit is prepared in a plus state, comprising:
performing a first NOT operation on a third qubit included in the quantum computing device, wherein the third qubit is prepared in the phased plus state;
computing a controlled adder operation on the first, second and third qubits, comprising encoding a result of the controlled adder operation in a fourth qubit included in the quantum computing device;
performing a square of the phase operation on the fourth qubit;
uncomputing the controlled adder operation on the first, second and third qubits;
performing a CNOT operation between the first qubit and the third qubit, wherein the first qubit acts as the control;
performing a CNOT operation between the second qubit and the third qubit, wherein the second qubit acts as the control; and
performing a second NOT operation on the third qubit.