US 11,900,220 B2
Method and apparatus for amplitude estimation of quantum circuit, storage medium, and electronic apparatus
Yewei Yuan, Hefei (CN); Ye Li, Hefei (CN); Ningbo An, Hefei (CN); and Menghan Dou, Hefei (CN)
Assigned to Origin Quantum Computing Technology (Hefei) Co., Ltd, Hefei (CN)
Filed by Origin Quantum Computing Technology (Hefei) Co., Ltd, Hefei (CN)
Filed on May 1, 2023, as Appl. No. 18/310,405.
Application 18/310,405 is a continuation of application No. PCT/CN2021/139174, filed on Dec. 17, 2021.
Claims priority of application No. 202011591351.6 (CN), filed on Dec. 29, 2020.
Prior Publication US 2023/0325697 A1, Oct. 12, 2023
Int. Cl. G06N 10/20 (2022.01); G06N 10/60 (2022.01)
CPC G06N 10/20 (2022.01) [G06N 10/60 (2022.01)] 10 Claims
OG exemplary drawing
 
1. A method for amplitude estimation of a quantum circuit, wherein the method is applied to a computer, a quantum virtual machine is built in the computer by using resources of the computer, a quantum program is running in the quantum virtual machine, the quantum program comprises a quantum circuit, wherein the method for amplitude estimation of a quantum circuit comprises:
determining a target quantum state of a target quantum bit in a target quantum circuit, calculating a first difference value between a current angle upper limit value and a current angle lower limit value that are corresponding to a to-be-estimated amplitude of the target quantum state, and determining the first difference value as a target difference;
determining, based on a preset intermediate variable parameter, the current angle upper limit value, and the current angle lower limit value, a next angle amplification factor and a next flag parameter that are corresponding to a next iteration step, when the target difference is greater than a preset precision threshold;
controlling a preset amplification quantum circuit to amplify the target quantum circuit by the next angle amplification factor, and measuring a target quantum state of the target quantum bit in the amplified target quantum circuit based on a preset total quantity of observation times;
calculating a second difference value between a next angle upper limit value and a next angle lower limit value of the to-be-estimated amplitude based on the current angle upper limit value, the current angle lower limit value, the next angle amplification factor, the next flag parameter, and a measurement result of the target quantum state, determining the second difference value as a target difference and repeating the process until the target difference is not greater than the precision threshold; and
determining, based on an angle upper limit value and an angle lower limit value that reach the precision threshold, a probability estimated value corresponding to a to-be-estimated quantum bit.