Lossless Postselected Quantum Metrology with Quasi-pure Mixed States

• URL: http://arxiv.org/abs/2405.00405v4
• Date: Sun, 12 Oct 2025 06:46:00 GMT
• Title: Lossless Postselected Quantum Metrology with Quasi-pure Mixed States
• Authors: Jing Yang,
• Abstract summary: We show that the quasi-pure structure can be universally engineered through only classical correlation with an ancilla.<n>Our findings extend the utility of postselection techniques to scenarios with decoherence and also offer new perspectives to foundational questions in quantum information geometry.
• Score: 4.280350793754043
• License: http://creativecommons.org/licenses/by/4.0/
• Abstract: Postselection can compress the metrological information and improve sensitivity in the presence of certain types of technical noise. Postselected quantum metrology with pure states has been significantly advanced recently. However, extending this framework to mixed states leads to formidable challenges, such as the difficulty in searching for lossless postselection measurements or even the loss of metrological information. In this work, we leverage the intuition for the lossless postselection of pure states and generalize the theory to the lossless postselection of a class of mixed states, dubbed quasi-pure states. We illustrate our findings in postselected quantum imaging, unitary estimation problems, and show that the quasi-pure structure can be universally engineered through only classical correlation with an ancilla. Our findings extend the utility of postselection techniques to scenarios with decoherence and also offer new perspectives to foundational questions in quantum information geometry.

Related papers

• Local-oscillator-agnostic squeezing detection [0.0]
  We address the problem of measuring nonclassicality in bosonic systems without having access to a known reference signal.<n>We construct broader classes of criteria for nonclassicality which allow us to investigate quantum phenomena regardless of the quantumness of selected subsystems.
  arXiv  Detail & Related papers  (2026-01-29T20:10:01Z)
• Robustness of quantum data hiding against entangled catalysts and memory [47.791962198275066]
  We develop a general framework for state discrimination that unifies catalytic and memory-assisted local discrimination protocols.<n>We prove that when the hiding states are separable, neither entangled catalysts nor quantum memory can increase the optimal discrimination probability.<n>In contrast, for some entangled states, a reusable quantum memory turns locally indistinguishable states into ones that can be discriminated almost perfectly.
  arXiv  Detail & Related papers  (2025-11-06T14:36:36Z)
• Tracking Quantum Dynamics in an Optical Cavity for Recovering Purity and Squeezing via Quantum State Smoothing [16.26939478187343]
  Loss of quantum information to the environment can be maximally extracted via acausal quantum state smoothing.<n>We show that smoothed states are better estimates of hidden true states than those from conventional filtering.<n>The estimation techniques used in this paper are promising for many applications in quantum information that incorporate post-processing.
  arXiv  Detail & Related papers  (2025-09-05T02:08:37Z)
• Grassmann Variational Monte Carlo with neural wave functions [45.935798913942904]
  We formalize the framework introduced by Pfau et al.citepfau2024accurate in terms of Grassmann geometry of the Hilbert space.<n>We validate our approach on the Heisenberg quantum spin model on the square lattice, achieving highly accurate energies and physical observables for a large number of excited states.
  arXiv  Detail & Related papers  (2025-07-14T13:53:13Z)
• Relieving the post-selection problem by quantum singular value transformation [9.861807368585373]
  We propose a post-selection-free experimental strategy based on a fully quantum approach. We deterministically simulate the post-selected quantum states by applying quantum singular value transformation algorithms. We also introduce a pseudoinverse decoder for measurement-induced quantum teleportation.
  arXiv  Detail & Related papers  (2025-03-31T18:00:31Z)
• A Retrodictive Approach to Quantum State Smoothing [4.059741577689775]
  We propose a novel definition of the smoothed quantum state based on quantum Bayesian retrodiction.<n>We show that this smoothed state has, on average, greater purity than the state reconstructed using just the prior information.
  arXiv  Detail & Related papers  (2025-01-27T12:14:54Z)
• Quasi-optimal sampling from Gibbs states via non-commutative optimal transport metrics [1.5999407512883517]
  We study the problem of sampling from and preparing quantum Gibbs states of local commuting Hamiltonians on hypercubic lattices of arbitrary dimension. We prove that any such Gibbs state which satisfies a clustering condition that we coin decay of matrix-valued quantum conditional mutual information can be quasi-optimally prepared on a quantum computer.
  arXiv  Detail & Related papers  (2024-12-02T17:25:24Z)
• The multimode conditional quantum Entropy Power Inequality and the squashed entanglement of the extreme multimode bosonic Gaussian channels [53.253900735220796]
  Inequality determines the minimum conditional von Neumann entropy of the output of the most general linear mixing of bosonic quantum modes. Bosonic quantum systems constitute the mathematical model for the electromagnetic radiation in the quantum regime.
  arXiv  Detail & Related papers  (2024-10-18T13:59:50Z)
• Quantum circuit design for mixture and preparation of arbitrary pure and mixed quantum states [25.01488143369413]
  This paper addresses the challenge of preparing arbitrary mixed quantum states. Two circuit design methods are presented: one via a mixture of pure states and the other via purification.
  arXiv  Detail & Related papers  (2024-03-28T06:37:00Z)
• Tight concentration inequalities for quantum adversarial setups exploiting permutation symmetry [0.5242869847419834]
  We show that our one-sided concentration inequalities for a quantum state require the $N$-qudit system to be permutation invariant. We numerically demonstrate the tightness of our bounds in simple quantum information processing tasks.
  arXiv  Detail & Related papers  (2024-03-18T12:20:46Z)
• Embezzling entanglement from quantum fields [41.94295877935867]
  Embezzlement of entanglement refers to the counterintuitive possibility of extracting entangled quantum states from a reference state of an auxiliary system. We uncover a deep connection between the operational task of embezzling entanglement and the mathematical classification of von Neumann algebras.
  arXiv  Detail & Related papers  (2024-01-14T13:58:32Z)
• Theory of free fermions dynamics under partial post-selected monitoring [49.1574468325115]
  We derive a partial post-selected Schrdinger"o equation based on a microscopic description of continuous weak measurement. We show that the passage to the monitored universality occurs abruptly at finite partial post-selection. Our approach establishes a way to study MiPTs for arbitrary subsets of quantum trajectories.
  arXiv  Detail & Related papers  (2023-12-21T16:53:42Z)
• Quantum algorithms: A survey of applications and end-to-end complexities [88.57261102552016]
  The anticipated applications of quantum computers span across science and industry.<n>We present a survey of several potential application areas of quantum algorithms.<n>We outline the challenges and opportunities in each area in an "end-to-end" fashion.
  arXiv  Detail & Related papers  (2023-10-04T17:53:55Z)
• 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)
• On the optimal error exponents for classical and quantum antidistinguishability [3.481985817302898]
  Antidistinguishability has been used to investigate the reality of quantum states. We show that the optimal error exponent vanishes to zero for classical and quantum antidistinguishability. It remains an open problem to obtain an explicit expression for the optimal error exponent for quantum antidistinguishability.
  arXiv  Detail & Related papers  (2023-09-07T14:03:58Z)
• Quantum circuits for measuring weak values, Kirkwood--Dirac quasiprobability distributions, and state spectra [0.0]
  We propose simple quantum circuits to measure weak values, KD distributions, and spectra of density matrices without the need for post-selection. An upshot is a unified view of nonclassicality in all those tasks.
  arXiv  Detail & Related papers  (2023-02-01T19:01:25Z)
• Suppressing Amplitude Damping in Trapped Ions: Discrete Weak Measurements for a Non-unitary Probabilistic Noise Filter [62.997667081978825]
  We introduce a low-overhead protocol to reverse this degradation. We present two trapped-ion schemes for the implementation of a non-unitary probabilistic filter against amplitude damping noise. This filter can be understood as a protocol for single-copy quasi-distillation.
  arXiv  Detail & Related papers  (2022-09-06T18:18:41Z)
• Improved Quantum Algorithms for Fidelity Estimation [77.34726150561087]
  We develop new and efficient quantum algorithms for fidelity estimation with provable performance guarantees. Our algorithms use advanced quantum linear algebra techniques, such as the quantum singular value transformation. We prove that fidelity estimation to any non-trivial constant additive accuracy is hard in general.
  arXiv  Detail & Related papers  (2022-03-30T02:02:16Z)
• Learning entanglement breakdown as a phase transition by confusion [0.0]
  We develop an approach for revealing entanglement breakdown using a machine learning technique, which is known as 'learning by confusion' We show that the developed method provides correct answers for a variety of states, including entangled states with positive partial transpose (PPT) We also present a more practical version of the method, which is suitable for studying entanglement breakdown in noisy intermediate-scale quantum (NISQ) devices.
  arXiv  Detail & Related papers  (2022-02-01T11:41:18Z)
• Scattering as a quantum metrology problem: a quantum walk approach [0.0]
  We address the scattering of a quantum particle by a one-dimensional barrier potential over a set of discrete positions. We formalize the problem as a continuous-time quantum walk on a lattice with an impurity, and use the quantum Fisher information as a mean to quantify the maximal possible accuracy in the estimation of the height of the barrier.
  arXiv  Detail & Related papers  (2020-10-23T14:42:25Z)
• Quantum information spreading in a disordered quantum walk [50.591267188664666]
  We design a quantum probing protocol using Quantum Walks to investigate the Quantum Information spreading pattern. We focus on the coherent static and dynamic disorder to investigate anomalous and classical transport. Our results show that a Quantum Walk can be considered as a readout device of information about defects and perturbations occurring in complex networks.
  arXiv  Detail & Related papers  (2020-10-20T20:03:19Z)
• The role of boundary conditions in quantum computations of scattering observables [58.720142291102135]
  Quantum computing may offer the opportunity to simulate strongly-interacting field theories, such as quantum chromodynamics, with physical time evolution. As with present-day calculations, quantum computation strategies still require the restriction to a finite system size. We quantify the volume effects for various $1+1$D Minkowski-signature quantities and show that these can be a significant source of systematic uncertainty.
  arXiv  Detail & Related papers  (2020-07-01T17:43:11Z)
• Einselection from incompatible decoherence channels [62.997667081978825]
  We analyze an open quantum dynamics inspired by CQED experiments with two non-commuting Lindblad operators. We show that Fock states remain the most robust states to decoherence up to a critical coupling.
  arXiv  Detail & Related papers  (2020-01-29T14:15:19Z)
• Effects of Postselected von Neumann Measurement on the Properties of Single-Mode Radiation Fields [0.0]
  Postselected von Neumann measurement characterized by postselection and weak value has been found potential applications in quantum metrology. As an application of this new measurement technique in quantum optics, its effects on the features of single-mode radiation fields are investigated.
  arXiv  Detail & Related papers  (2019-12-31T09:04:22Z)

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.