	US 12,242,562 B2
	Systems and methods for enhanced eigenvalue inversion using quantum conditional logic
Romina Yalovetzky, Buenos Aires (AR); Dylan Herman, Woodcliff Lake, NJ (US); Pierre Minssen, New York, NY (US); Marco Pistoia, Amawalk, NY (US); Alexander Buts, Vernon Hills, IL (US); and Shaohan Hu, Yorktown Heights, NY (US)
Assigned to JPMORGAN CHASE BANK, N.A., New York, NY (US)
Filed by JPMORGAN CHASE BANK, N.A., New York, NY (US)
Filed on May 26, 2021, as Appl. No. 17/331,445.
Prior Publication US 2022/0382827 A1, Dec. 1, 2022
Int. Cl. G06F 17/12 (2006.01); G06F 17/16 (2006.01); G06N 10/00 (2022.01)

CPC G06F 17/12 (2013.01) [G06F 17/16 (2013.01); G06N 10/00 (2019.01)]

4 Claims

1. A classical computer, comprising:

a computer processor; and

a memory storing a classical computer program;

wherein the classical computer program is configured to generate a quantum computer program comprising instructions to:

initialize a register to an initial state;

initialize an ancilla qubit and apply a Hadamard gate to the ancilla qubit;

determine a number of iterations n to estimate n-bit eigenvalues;

perform a first unitary gate raised to 2ⁿ⁻¹and controlled by the ancilla qubit;

perform a Hadamard gate on the ancilla qubit;

measure the ancilla qubit and save in a classical register C₀;

clear the ancilla qubit;

initialize a counter i to n−2;

perform a second unitary gate raised to 2ⁱand controlled by the ancilla qubit;

perform a phase gate on the ancilla qubit conditioned on a value in a classical register C_{(n−1)−i−1}and apply a Hadamard gate on the ancilla qubit;

measure the ancilla qubit and save in a classical register C_(n−1)−i;

clear the ancilla qubit; and

decrease i by 1 and repeating the performing of the second unitary gate, the performing of the phase gate, the applying of the Hadamard gate,

the measuring of the ancilla qubit, the saving of the ancilla qubit, and the decreasing of i by 1 until i is equal to zero;

wherein the classical computer program sends the quantum computer program to a quantum computer, the quantum computer executes the quantum computer program, receives results from the quantum computer in the classical registers C₀, C₁, . . . C_n−1, and outputs the results.