Combining critical and quantum metrology

• URL: http://arxiv.org/abs/2311.16472v2
• Date: Fri, 9 Feb 2024 16:51:39 GMT
• Title: Combining critical and quantum metrology
• Authors: Christoph Hotter, Helmut Ritsch, and Karol Gietka
• Abstract summary: We introduce an approach combining two methodologies into a unified protocol applicable to closed and driven-dissipative systems. We provide analytical expressions for the quantum and classical Fisher information in such a setup, elucidating as well a straightforward measurement approach. We showcase these results by focusing on the squeezing Hamiltonian, which characterizes the thermodynamic limit of Dicke and Lipkin-Meshkov-Glick Hamiltonians.
• Score: 0.0
• License: http://creativecommons.org/licenses/by/4.0/
• Abstract: Critical metrology relies on the precise preparation of a system in its ground state near a quantum phase transition point where quantum correlations get very strong. Typically this increases the quantum Fisher information with respect to changes in system parameters and thus improves the optimally possible measurement precision limited by the Cram\'er-Rao bound. Hence critical metrology involves encoding information about the unknown parameter in changes of the system's ground state. Conversely, in conventional metrology methods like Ramsey interferometry, the eigenstates of the system remain unchanged, and information about the unknown parameter is encoded in the relative phases that excited system states accumulate during their time evolution. Here we introduce an approach combining these two methodologies into a unified protocol applicable to closed and driven-dissipative systems. We show that the quantum Fisher information in this case exhibits an additional interference term originating from the interplay between eigenstate and relative phase changes. We provide analytical expressions for the quantum and classical Fisher information in such a setup, elucidating as well a straightforward measurement approach that nearly attains the maximum precision permissible under the Cram\'er-Rao bound. We showcase these results by focusing on the squeezing Hamiltonian, which characterizes the thermodynamic limit of Dicke and Lipkin-Meshkov-Glick Hamiltonians.

Related papers

• Enhancing Gaussian quantum metrology with position-momentum correlations [0.0]
  We employ a correlated Gaussian wave packet as a probe to examine the dynamics of Quantum Fisher Information (QFI) and purity based on PM correlations. In the low-temperature regime, we find an improvement in the thermometry of the surrounding environment when the original system exhibits a non-null initial correlation.
  arXiv  Detail & Related papers  (2024-08-23T13:34:05Z)
• Quantum information scrambling in adiabatically-driven critical systems [49.1574468325115]
  Quantum information scrambling refers to the spread of the initially stored information over many degrees of freedom of a quantum many-body system. We extend the notion of quantum information scrambling to critical quantum many-body systems undergoing an adiabatic evolution.
  arXiv  Detail & Related papers  (2024-08-05T18:00:05Z)
• Multiparameter critical quantum metrology with impurity probes [0.0]
  We introduce the two-impurity Kondo (2IK) model as a novel paradigm for critical quantum metrology. We demonstrate that by applying a known control field, the singularity can be removed and measurement sensitivity restored.
  arXiv  Detail & Related papers  (2023-11-28T16:32:51Z)
• Decoherence time in quantum harmonic oscillators as quantum memory systems [0.7252027234425334]
  This paper is concerned with open quantum harmonic oscillators (OQHOs) described by linear quantum differential equations. In a more realistic case of system-environment coupling, we define a memory decoherence horizon as a typical time for a mean-square deviation of the system variables. We consider the decoherence time over the energy and coupling matrix of the OQHO as a memory system in its storage phase and obtain a condition under which the zero Hamiltonian delivers a suboptimal solution.
  arXiv  Detail & Related papers  (2023-10-26T08:29:42Z)
• Enhanced Entanglement in the Measurement-Altered Quantum Ising Chain [46.99825956909532]
  Local quantum measurements do not simply disentangle degrees of freedom, but may actually strengthen the entanglement in the system. This paper explores how a finite density of local measurement modifies a given state's entanglement structure.
  arXiv  Detail & Related papers  (2023-10-04T09:51:00Z)
• Quantifying measurement-induced quantum-to-classical crossover using an open-system entanglement measure [49.1574468325115]
  We study the entanglement of a single particle under continuous measurements. We find that the entanglement at intermediate time scales shows the same qualitative behavior as a function of the measurement strength.
  arXiv  Detail & Related papers  (2023-04-06T09:45:11Z)
• On optimization of coherent and incoherent controls for two-level quantum systems [77.34726150561087]
  This article considers some control problems for closed and open two-level quantum systems. The closed system's dynamics is governed by the Schr"odinger equation with coherent control. The open system's dynamics is governed by the Gorini-Kossakowski-Sudarshan-Lindblad master equation.
  arXiv  Detail & Related papers  (2022-05-05T09:08:03Z)
• Enhanced nonlinear quantum metrology with weakly coupled solitons and particle losses [58.720142291102135]
  We offer an interferometric procedure for phase parameters estimation at the Heisenberg (up to 1/N) and super-Heisenberg scaling levels. The heart of our setup is the novel soliton Josephson Junction (SJJ) system providing the formation of the quantum probe. We illustrate that such states are close to the optimal ones even with moderate losses.
  arXiv  Detail & Related papers  (2021-08-07T09:29:23Z)
• Quantum Fisher information measurement and verification of the quantum Cram\'er-Rao bound in a solid-state qubit [11.87072483257275]
  We experimentally demonstrate near saturation of the quantum Cram'er-Rao bound in the phase estimation of a solid-state spin system. This is achieved by comparing the experimental uncertainty in phase estimation with an independent measurement of the related quantum Fisher information.
  arXiv  Detail & Related papers  (2020-03-18T17:51:06Z)
• In and out of equilibrium quantum metrology with mean-field quantum criticality [68.8204255655161]
  We study the influence that collective transition phenomena have on quantum metrological protocols. The single spherical quantum spin (SQS) serves as stereotypical toy model that allows analytical insights on a mean-field level.
  arXiv  Detail & Related papers  (2020-01-09T19:20:42Z)

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.