Multiple‐Qubit C_kU^m Logic Gates of Rydberg Atoms via Optimized Geometric Quantum Operations

Abstract

Multiple-qubit logic gates, as an essential part of quantum logic gates, have wide practical application in quantum computation. Here, a scheme to directly construct a multiple-qubit logic gate C k U m , in which k control atoms apply an universal operation U on each of m target qubits in the Rydberg atom system is proposed. The scheme, based on Rydberg blockade and geometric quantum operations as well as optimized control theory, can greatly reduce the qubit number and the operation steps, improving the speed and robustness of the gating compared to the conventional multiple-qubit gates consisting of single-and two-qubit gates. Taking the C 2 U 2 gate as an example, the performance of the proposal is numerically evaluated in terms of the fidelity of the quantum gate as well as the robustness against the static systematic errors and spontaneous emission. This work may provide a significative reference for constructing universal multiple-qubit logic gates in future Rydberg atom experiments.