Neutral-atom quantum computation using multi-qubit geometric gates via adiabatic passage

TL;DR

This paper proposes a robust, scalable method for implementing multi-qubit geometric gates in neutral atom quantum computers using adiabatic passage, demonstrating high fidelity and resilience to errors.

Contribution

It introduces a double-STIRAP pulse sequence for multi-qubit geometric gates that are individually addressable and require no extra laser on target atoms, enhancing scalability and robustness.

Findings

Achieves 98-99% gate fidelity within 0.6 μs

Demonstrates strong resilience to Rabi frequency and position fluctuations

Successfully simulates Grover's algorithm for up to four qubits

Abstract

Adiabatic geometric phase gates offer enhanced robustness against fluctuations compared to con- ventional Rydberg blockade-based phase gates that rely on dynamical phase accumulation. We theoretically demonstrate two- and multi-qubit phase gates in a neutral atom architecture, relying on a double stimulated Raman adiabatic passage (double-STIRAP) pulse sequence that imprints a controllable geometric phase on the qubit systems. The system is designed in such a way that every atom is individually addressable, and moreover, no extra laser is required to be applied on the target atom while scaling up the system from two- to multi-qubit quantum gates. The gate fidelity has been numerically analyzed by changing the gate operation time, and we find that 98% to 99% fidelity can be achieved for gate time $\simeq$ 0.6 $\mu$s. We perform a systematic error analysis, which re- veals that our proposed gates can exhibit strong resilience against fluctuations in Rabi frequencies, finite blockade strength, and atomic position variations. These results establish our approach as a physically feasible and scalable pathway toward fault-tolerant quantum computation with neutral atoms. We simulate Grover's search algorithm for two-, three-, and four-qubit systems with high success probability and thereby demonstrate the utility and scalability of our proposed gates for quantum computation.