US 11,928,586 B2
Quantum computation through reinforcement learning
Yuezhen Niu, El Segundo, CA (US); Hartmut Neven, Malibu, CA (US); Vadim Smelyanskiy, Mountain View, CA (US); and Sergio Boixo Castrillo, Rancho Palos Verdes, CA (US)
Assigned to Google LLC, Mountain View, CA (US)
Appl. No. 16/962,059
Filed by Google LLC, Mountain View, CA (US)
PCT Filed Jan. 31, 2018, PCT No. PCT/US2018/016238
§ 371(c)(1), (2) Date Jul. 14, 2020,
PCT Pub. No. WO2019/152020, PCT Pub. Date Aug. 8, 2019.
Prior Publication US 2020/0410343 A1, Dec. 31, 2020
Int. Cl. G06N 3/08 (2023.01); G06N 10/00 (2022.01)
CPC G06N 3/08 (2013.01) [G06N 10/00 (2019.01)] 19 Claims
OG exemplary drawing
 
1. A computer implemented method for designing a quantum control trajectory for implementing a quantum gate using quantum hardware, the method comprising:
representing, by a classical processor, the quantum gate as a sequence of control actions;
applying, by a classical processor, a reinforcement learning model to iteratively adjust each control action in the sequence of control actions to determine a quantum control trajectory that implements the quantum gate and reduces leakage, infidelity and total runtime of the quantum gate during the iterative adjustments, comprising, for each iteration:
determining, by an agent, a control action for the iteration based on a current state of a quantum system included in the quantum hardware;
updating, by a training environment, the current state of the quantum system to a subsequent state of the quantum system using the determined control action and sample control noise;
determining, by the agent, a discounted future reward using i) a universal control cost function that penalizes leakage, infidelity and total gate runtime as a reinforcement learning discounted future reward function and ii) the updated state of the quantum system; and
adjusting, by the agent and based on the determined discounted future reward, values of one or more control trajectory parameters for the iteration; and
implementing, by the quantum hardware, the quantum gate using the quantum control trajectory.