# Eliminating qubit type cross-talk in the $\textit{omg}$ protocol

**Authors:** Samuel R. Vizvary, Zachary J. Wall, Matthew J. Boguslawski, Michael Bareian, Andrei Derevianko, Wesley C. Campbell, Eric R. Hudson  
**arXiv:** [2310.10905](https://arxiv.org/abs/2310.10905)  
**Date:** 2023-10-17  
**Summary page:** https://www.summarizepaper.com/en/arxiv-id/2310.10905v1/

## Key points

- Cutting-edge approach leveraging multiple, application-specific qubit subspaces within the Hilbert space of individual atoms
- Fundamental requirement: ability to access subspaces independently without causing detrimental effects on other subspaces
- Intensity noise during laser-based quantum gates in one subspace can lead to decoherence in other subspaces
- Solution involves implementing a specific polarization for gate lasers dependent on the magnetic field
- Technique is straightforward and shows promise in enhancing OMG-based quantum technology performance
- Experimental results demonstrate efficacy of the approach, leading to significant improvement in coherence time from 30ms to 3.5 ± 2.6 s
- Importance of mitigating cross-talk and decoherence effects in multi-qubit systems like those used in OMG protocol
- Use of magnetic-field-induced vector light shifts as a promising strategy for enhancing quantum information processing capabilities

## Summary

The  is a cutting-edge approach that leverages multiple, application-specific qubit subspaces within the Hilbert space of individual atoms for . A fundamental requirement for successful operation is the ability to access these subspaces independently without causing detrimental effects on information stored in other subspaces. However, our research has revealed that intensity noise during laser-based quantum gates in one subspace can lead to  in other subspaces, potentially complicating the effectiveness of OMG operations. To address this challenge, we have identified a solution involving a . By implementing a specific polarization for the gate lasers dependent on the magnetic field, we can effectively eliminate this source of decoherence. This technique is relatively straightforward to implement and shows promise in enhancing the performance of OMG-based quantum technology. Furthermore, our experimental results demonstrate the efficacy of this approach. By setting the polarization to a "magic" value through precise adjustments using a quarter waveplate and rotation mount, we were able to minimize differential light shifts in certain qubits and shield them from high-frequency intensity fluctuations. This optimization led to a significant improvement in coherence time, with an increase from 30ms to 3.5 ± 2.6 s observed in our experiments. Overall, our findings highlight the importance of mitigating cross-talk and decoherence effects in multi-qubit systems like those utilized in the OMG protocol. The use of magnetic-field-induced vector light shifts represents a promising strategy for enhancing quantum information processing capabilities and advancing the development of quantum technologies based on OMG principles.