Quantum Metrology with Coherent Superposition of Two Different Coded Channels

• URL: http://arxiv.org/abs/2012.01899v1
• Date: Thu, 3 Dec 2020 13:25:16 GMT
• Title: Quantum Metrology with Coherent Superposition of Two Different Coded Channels
• Authors: Dong Xie, Chunling Xu, An Min Wang
• Abstract summary: We show that the Heisenberg limit $1/N$ can be beaten by the coherent superposition without the help of indefinite causal order. We analytically obtain the general form of estimation precision in terms of the quantum Fisher information. Our results can help to construct a high-precision measurement equipment.
• Score: 1.430924337853801
• License: http://creativecommons.org/licenses/by/4.0/
• Abstract: We investigate the advantage of coherent superposition of two different coded channels in quantum metrology. In a continuous variable system, we show that the Heisenberg limit $1/N$ can be beaten by the coherent superposition without the help of indefinite causal order. And in parameter estimation, we demonstrate that the strategy with the coherent superposition can perform better than the strategy with quantum \textsc{switch} which can generate indefinite causal order. We analytically obtain the general form of estimation precision in terms of the quantum Fisher information and further prove that the nonlinear Hamiltonian can improve the estimation precision and make the measurement uncertainty scale as $1/N^m$ for $m\geq2$. Our results can help to construct a high-precision measurement equipment, which can be applied to the detection of coupling strength and the test of time dilation and the modification of the canonical commutation relation.

Related papers

• Quantum error correction-inspired multiparameter quantum metrology [0.029541734875307393]
  We present a strategy for obtaining optimal probe states and measurement schemes in a class of noiseless estimation problems with symmetry among the generators. The key to the framework is the introduction of a set of quantum metrology conditions, analogous to the quantum error correction conditions of Knill and Laflamme. We show that tetrahedral symmetry and, with fine-tuning, $S_3$ symmetry, are minimal symmetry groups providing optimal probe states for SU(2) estimation.
  arXiv  Detail & Related papers  (2024-09-25T00:06:12Z)
• Optimal Low-Depth Quantum Signal-Processing Phase Estimation [0.029541734875307393]
  We introduce Quantum Signal-Processing Phase Estimation algorithms that are robust against challenges and achieve optimal performance. Our approach achieves an unprecedented standard deviation accuracy of $10-4$ radians for estimating unwanted swap angles in superconducting two-qubit experiments. Our results are rigorously validated against the quantum Fisher information, confirming our protocol's ability to achieve unmatched precision for two-qubit gate learning.
  arXiv  Detail & Related papers  (2024-06-17T10:33:52Z)
• Quantum-Enhanced Parameter Estimation Without Entanglement [0.0]
  We construct analogues of Dicke and GHZ states on a single $N+1$ dimensional qudit. We estimate the achievable precision, suggesting a close relationship between non-classical states and metrological power of qudits.
  arXiv  Detail & Related papers  (2023-09-25T17:57:45Z)
• Sequential Quantum Channel Discrimination [19.785872350085878]
  We consider the sequential quantum channel discrimination problem using adaptive and non-adaptive strategies. We show that both types of error probabilities decrease to zero exponentially fast. We conjecture that the achievable rate region is not larger than that achievable with POVMs.
  arXiv  Detail & Related papers  (2022-10-20T08:13:39Z)
• 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)
• 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)
• Quantum probes for the characterization of nonlinear media [50.591267188664666]
  We investigate how squeezed probes may improve individual and joint estimation of the nonlinear coupling $tildelambda$ and of the nonlinearity order $zeta$. We conclude that quantum probes represent a resource to enhance precision in the characterization of nonlinear media, and foresee potential applications with current technology.
  arXiv  Detail & Related papers  (2021-09-16T15:40:36Z)
• Incompatibility measures in multi-parameter quantum estimation under hierarchical quantum measurements [4.980960723762946]
  We show an approach to study the incompatibility under general $p$-local measurements. We demonstrate the power of the approach by presenting a hierarchy of analytical bounds on the tradeoff.
  arXiv  Detail & Related papers  (2021-09-13T09:33:47Z)
• 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)
• Realization of arbitrary doubly-controlled quantum phase gates [62.997667081978825]
  We introduce a high-fidelity gate set inspired by a proposal for near-term quantum advantage in optimization problems. By orchestrating coherent, multi-level control over three transmon qutrits, we synthesize a family of deterministic, continuous-angle quantum phase gates acting in the natural three-qubit computational basis.
  arXiv  Detail & Related papers  (2021-08-03T17:49:09Z)
• Quantum Statistical Complexity Measure as a Signalling of Correlation Transitions [55.41644538483948]
  We introduce a quantum version for the statistical complexity measure, in the context of quantum information theory, and use it as a signalling function of quantum order-disorder transitions. We apply our measure to two exactly solvable Hamiltonian models, namely: the $1D$-Quantum Ising Model and the Heisenberg XXZ spin-$1/2$ chain. We also compute this measure for one-qubit and two-qubit reduced states for the considered models, and analyse its behaviour across its quantum phase transitions for finite system sizes as well as in the thermodynamic limit by using Bethe ansatz.
  arXiv  Detail & Related papers  (2020-02-05T00:45:21Z)

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.