Scrambling for precision: optimizing multiparameter qubit estimation in the face of sloppiness and incompatibility

Fuente: arXiv
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Main Authors: He, Jiayu, Paris, Matteo G. A.
Format: Preprint
Published: 2025
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author He, Jiayu
Paris, Matteo G. A.
author_facet He, Jiayu
Paris, Matteo G. A.
contents Multiparameter quantum estimation theory plays a crucial role in advancing quantum metrology. Recent studies focused on fundamental challenges such as enhancing precision in the presence of incompatibility or sloppiness, yet the relationship between these features remains poorly understood. In this work, we explore the connection between sloppiness and incompatibility by introducing an adjustable scrambling operation for parameter encoding. Using a minimal yet versatile two-parameter qubit model, we examine the trade-off between sloppiness and incompatibility and discuss: (1) how information scrambling can improve estimation, and (2) how the correlations between the parameters and the incompatibility between the symmetric logarithmic derivatives impose constraints on the ultimate quantum limits to precision. Through analytical optimization, we identify strategies to mitigate these constraints and enhance estimation efficiency. We also compare the performance of joint parameter estimation to strategies involving successive separate estimation steps, demonstrating that the ultimate precision can be achieved when sloppiness is minimized. Our results provide a unified perspective on the trade-offs inherent to multiparameter qubit statistical models, offering practical insights for optimizing experimental designs.
format Preprint
id arxiv_https___arxiv_org_abs_2503_08235
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Scrambling for precision: optimizing multiparameter qubit estimation in the face of sloppiness and incompatibility
He, Jiayu
Paris, Matteo G. A.
Quantum Physics
Mathematical Physics
Multiparameter quantum estimation theory plays a crucial role in advancing quantum metrology. Recent studies focused on fundamental challenges such as enhancing precision in the presence of incompatibility or sloppiness, yet the relationship between these features remains poorly understood. In this work, we explore the connection between sloppiness and incompatibility by introducing an adjustable scrambling operation for parameter encoding. Using a minimal yet versatile two-parameter qubit model, we examine the trade-off between sloppiness and incompatibility and discuss: (1) how information scrambling can improve estimation, and (2) how the correlations between the parameters and the incompatibility between the symmetric logarithmic derivatives impose constraints on the ultimate quantum limits to precision. Through analytical optimization, we identify strategies to mitigate these constraints and enhance estimation efficiency. We also compare the performance of joint parameter estimation to strategies involving successive separate estimation steps, demonstrating that the ultimate precision can be achieved when sloppiness is minimized. Our results provide a unified perspective on the trade-offs inherent to multiparameter qubit statistical models, offering practical insights for optimizing experimental designs.
title Scrambling for precision: optimizing multiparameter qubit estimation in the face of sloppiness and incompatibility
topic Quantum Physics
Mathematical Physics
url https://arxiv.org/abs/2503.08235