Spin Grid States for Quantum Metrology in Atomic Clocks Limited by Spontaneous Emission

• URL: http://arxiv.org/abs/2609.16975v1
• Date: Tue, 15 Sep 2026 10:50:47 GMT
• Title: Spin Grid States for Quantum Metrology in Atomic Clocks Limited by Spontaneous Emission
• Abstract summary: Entanglement can enhance precision in phase estimation and in frequency estimation with atomic clocks.<n>We study quantum metrology with an ensemble of atoms subject to spontaneous emission.
• Score: 0.0
• License: http://creativecommons.org/licenses/by/4.0/
• Abstract: Entanglement can enhance precision in phase estimation and in frequency estimation with atomic clocks, but it remains a central challenge to identify useful states and measurements under realistic noise processes. Here, we study quantum metrology with an ensemble of atoms subject to spontaneous emission, which limits frequency estimation by constraining the useful interrogation time. We identify spin grid states (SGSs) as the relevant near-optimal probes beyond a crossover at an ensemble size of 51, where GHZ-like states cease to be optimal. SGSs display a periodic grid on the Bloch sphere and can be generated with two one-axis-twisting (OAT) operations separated by a collective rotation. By optimizing the quantum Fisher information over permutationally symmetric states, we find that SGSs perform close to the globally optimal probes for intermediate and large ensembles, which turn out to be spin GKP states. We further present a sequential readout strategy that nearly saturates the corresponding quantum Fisher information. This strategy uses an OAT echo to map spontaneous-emission events onto collective rotations, making the corresponding jump sectors distinguishable and allowing the measurement basis to be conditioned on the number of decay events. Together, these results show that SGSs provide a practical route to quantum-enhanced phase and frequency metrology in atomic ensembles limited by spontaneous emission.

Related papers

• Identifying quantum coherence in quantum annealers [37.067444579637076]
  We use many-body coherent oscillations (MBCO) as a diagnostic for the identification of system-wide coherence in analog quantum simulators.<n>This work gives a general roadmap for the search for quantum coherence in noisy, large-scale quantum platforms.
  arXiv  Detail & Related papers  (2026-02-24T20:39:41Z)
• Phase transitions, symmetries, and tunneling in Kerr parametric oscillators [37.69303106863453]
  We study the onset of ground-state and excited-state quantum phase transitions in KPOs.<n>We identify the critical points associated with quantum phase transitions and analyze their influence on the energy spectrum and tunneling dynamics.<n>Our findings provide insights into the engineering of robust quantum states, quantum dynamics control, and onset of quantum phase transitions with implications for critical quantum sensing.
  arXiv  Detail & Related papers  (2025-04-21T18:00:19Z)
• Credible-interval-based adaptive Bayesian quantum frequency estimation for entanglement-enhanced atomic clocks [2.949988100814893]
  Entanglement-enhanced quantum sensors encounter a fundamental trade-off: while entanglement improves precision to the Heisenberg limit, it restricts dynamic range.<n>We present a credible-interval-based adaptive Bayesian quantum frequency estimation protocol for atomic clocks.<n>Our protocol is more stable against noise and more robust to dephasing than existing adaptive schemes.
  arXiv  Detail & Related papers  (2024-11-22T13:57:32Z)
• 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)
• Non-resonant electric quantum control of individual on-surface spins [41.94295877935867]
  Quantum control techniques play an important role in manipulating and harnessing the properties of different quantum systems.<n>We propose to achieve quantum control over a single on-surface atomic spin using Landau-Zener-St"uckelberg-Majorana (LZSM) interferometry.
  arXiv  Detail & Related papers  (2024-04-29T18:23:30Z)
• Qubit-assisted quantum metrology under a time-reversal strategy [2.4927008953071725]
  We propose a quantum metrology protocol based on a two-step joint evolution of the probe system and an ancillary qubit and quantum measurement.<n>We show that the quantum Fisher information (QFI) about the phase parameter encoded in the probe system is determined by the expectation value of the square of a phase generator.
  arXiv  Detail & Related papers  (2024-04-19T06:25:13Z)
• Universal quantum operations and ancilla-based readout for tweezer clocks [3.2810235099960297]
  We show universal quantum operations and ancilla-based readout for ultranarrow optical transitions of neutral atoms. Our work lays the foundation for hybrid processor-clock devices with neutral atoms and points to a future of practical applications for quantum processors linked with quantum sensors.
  arXiv  Detail & Related papers  (2024-02-25T23:35:36Z)
• Robustness of the projected squeezed state protocol [0.0]
  Projected squeezed (PS) states are multipartite entangled states generated by unitary spin squeezing. We simulate the generation of PS states in non-ideal experimental conditions with relevant decoherence channels. Our findings highlight PS states as useful metrological resources, demonstrating a robustness against environmental effects with increasing qubit number N.
  arXiv  Detail & Related papers  (2023-10-18T13:21:44Z)
• Finite Pulse-Time Effects in Long-Baseline Quantum Clock Interferometry [45.73541813564926]
  We study the interplay of the quantum center-of-mass $-$ that can become delocalized $-$ together with the internal clock transitions. We show at the example of a Gaussian laser beam that the proposed quantum-clock interferometers are stable against perturbations from varying optical fields.
  arXiv  Detail & Related papers  (2023-09-25T18:00:03Z)
• 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)

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.