Real-time optimal quantum control for atomic magnetometers with decoherence

• URL: http://arxiv.org/abs/2512.05265v1
• Date: Thu, 04 Dec 2025 21:38:39 GMT
• Title: Real-time optimal quantum control for atomic magnetometers with decoherence
• Authors: Julia Amoros-Binefa,
• Abstract summary: We apply continuous quantum measurements and estimation theory to optical atomic magnetometers to achieve optimal sensitivity.<n>We derive a fundamental quantum limit on sensitivity that scales at best linearly with sensing time and atom number N.<n>Our strategy can also track biologically relevant signals, such as heartbeat-like waveforms, and drive the atomic ensemble into an entangled state.
• Score: 0.0
• License: http://creativecommons.org/licenses/by/4.0/
• Abstract: Quantum entanglement, in the form of spin squeezing, is known to improve the sensitivity of atomic sensors to static or slowly varying fields. Sensing transient events presents a distinct challenge, requires different analysis tools, and has not been shown to benefit from entanglement in practically important scenarios such as spin-precession magnetometry. To address this, we apply concepts from continuous quantum measurements and estimation theory to optical atomic magnetometers, aiming to accurately model these devices, interpret their measurement data, control their dynamics, and achieve optimal sensitivity. Quantifying this optimal performance requires determining a fundamental quantum limit on sensitivity. We derive this limit, imposed by noise, and show that it scales at best linearly with sensing time and atom number N, ruling out any super-classical scaling. This limit is independent of the initial state, measurement, estimator, and measurement-based feedback, and depends only on the decoherence model and the strength of field fluctuations. Thus, finding an estimator that attains this bound proves the sensing strategy optimal. To approach this limit, we develop a quantum dynamical model scalable with N, based on a co-moving Gaussian approximation of the stochastic master equation, which includes measurement backaction and decoherence. This enables a real-time estimation and control architecture integrating an extended Kalman filter with a linear quadratic regulator. Simulating the magnetometer with our model and EKF+LQR strategy shows that quantum-limited tracking of constant and fluctuating fields is within reach of current atomic magnetometers. Our sensing strategy can also track biologically relevant signals, such as heartbeat-like waveforms, and drive the atomic ensemble into an entangled state, even when the measurement record is used for feedback but later discarded.

Related papers

• Estimating ground-state properties in quantum simulators with global control [35.3616472951301]
  Accurately determining ground-state properties of quantum many-body systems remains one of the major challenges of quantum simulation.<n>We present a protocol for estimating the ground-state energy using only global time evolution under a target Hamiltonian.
  arXiv  Detail & Related papers  (2025-11-06T15:08:00Z)
• Towards Quantum Enhanced Adversarial Robustness with Rydberg Reservoir Learning [45.92935470813908]
  Quantum computing reservoir (QRC) leverages the high-dimensional, nonlinear dynamics inherent in quantum many-body systems.<n>Recent studies indicate that perturbation quantums based on variational circuits remain susceptible to adversarials.<n>We investigate the first systematic evaluation of adversarial robustness in a QR based learning model.
  arXiv  Detail & Related papers  (2025-10-15T12:17:23Z)
• Calibration of Quantum Devices via Robust Statistical Methods [45.464983015777314]
  We numerically analyze advanced statistical methods for Bayesian inference against the state-of-the-art in quantum parameter learning.<n>We show advantages of these approaches over existing ones, namely under multi-modality and high dimensionality.<n>Our findings have applications in challenging quantumcharacterization tasks namely learning the dynamics of open quantum systems.
  arXiv  Detail & Related papers  (2025-07-09T15:22:17Z)
• Thermalization and Criticality on an Analog-Digital Quantum Simulator [133.58336306417294]
  We present a quantum simulator comprising 69 superconducting qubits which supports both universal quantum gates and high-fidelity analog evolution. We observe signatures of the classical Kosterlitz-Thouless phase transition, as well as strong deviations from Kibble-Zurek scaling predictions. We digitally prepare the system in pairwise-entangled dimer states and image the transport of energy and vorticity during thermalization.
  arXiv  Detail & Related papers  (2024-05-27T17:40:39Z)
• Noisy atomic magnetometry with Kalman filtering and measurement-based feedback [0.0]
  We propose a comprehensive approach that integrates measurement, estimation and control strategies.<n>This involves implementing a quantum non-demolition measurement based on continuous light-probing of the atomic ensemble.<n>Thanks to the feedback proposed, the atoms exhibit entanglement even when the measurement data is discarded.
  arXiv  Detail & Related papers  (2024-03-21T18:11:09Z)
• A Floquet-Rydberg quantum simulator for confinement in $\mathbb{Z}_2$ gauge theories [44.99833362998488]
  Recent advances in the field of quantum technologies have opened up the road for the realization of small-scale quantum simulators. We present a scalable Floquet scheme for the quantum simulation of the real-time dynamics in a $mathbbZ$ LGT. We show that an observation of gauge-invariant confinement dynamics in the Floquet-Rydberg setup is at reach of current experimental techniques.
  arXiv  Detail & Related papers  (2023-11-28T13:01:24Z)
• Universality of critical dynamics with finite entanglement [68.8204255655161]
  We study how low-energy dynamics of quantum systems near criticality are modified by finite entanglement. Our result establishes the precise role played by entanglement in time-dependent critical phenomena.
  arXiv  Detail & Related papers  (2023-01-23T19:23:54Z)
• Probing finite-temperature observables in quantum simulators of spin systems with short-time dynamics [62.997667081978825]
  We show how finite-temperature observables can be obtained with an algorithm motivated from the Jarzynski equality. We show that a finite temperature phase transition in the long-range transverse field Ising model can be characterized in trapped ion quantum simulators.
  arXiv  Detail & Related papers  (2022-06-03T18:00:02Z)
• Criticality-Enhanced Quantum Sensing via Continuous Measurement [1.433758865948252]
  We propose a protocol for criticality-enhanced sensing via continuous observation of the emitted radiation quanta. We derive universal scaling laws featuring transient and long-time behavior governed by the underlying critical exponents. Our protocol is applicable to generic quantum-optical open sensors permitting continuous readout.
  arXiv  Detail & Related papers  (2021-08-13T18:01:02Z)
• Noisy atomic magnetometry in real time [0.0]
  Continuously monitored atomic spin-ensembles allow, in principle, for real-time sensing of external magnetic fields. We study how conclusions based on Kalman filtering methods change when inevitable imperfections are taken into account. We prove that even an infinitesimal amount of noise disallows the error to be arbitrarily diminished.
  arXiv  Detail & Related papers  (2021-03-22T17:28:40Z)
• Real-time optimal quantum control of mechanical motion at room temperature [4.050112001048099]
  We show real-time optimal control of the quantum trajectory of an optically trapped nanoparticles. In combination with levitation, this paves the way to full-scale control over the wavepacket dynamics of macroscopic quantum objects.
  arXiv  Detail & Related papers  (2020-12-30T15:14:11Z)

This list is automatically generated from the titles and abstracts of the papers in this site.

This site does not guarantee the quality of this site (including all information) and is not responsible for any consequences.