Indefinite Time Directed Quantum Metrology

• URL: http://arxiv.org/abs/2502.18264v2
• Date: Wed, 26 Feb 2025 08:51:24 GMT
• Title: Indefinite Time Directed Quantum Metrology
• Authors: Gaurang Agrawal, Pritam Halder, Aditi Sen De,
• Abstract summary: We show that our protocol can achieve Heisenberg scaling (1/N) with product probe states, surpassing the standard quantum limit (1/sqrtN)<n>Although we analytically prove the optimality of the symmetric product probe state in ITDM, entangled probe states produce a higher QFI than optimal product probes without enhancing scaling.<n>Our findings reveal the best orientation of product probe states in every pertinent situation, emphasizing its independence from the parameter to be estimated in the limiting case.
• Score: 0.0
• License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/
• Abstract: We explore the performance of the metrology scheme by employing a quantum time flip during encoding, a specific case of processes with indefinite time direction, which we refer to as indefinite time directed metrology (ITDM). In the case of single parameter estimation of a unitary, we demonstrate that our protocol can achieve Heisenberg scaling (1/N) with product probe states, surpassing the standard quantum limit (1/\sqrt{N}), where N is the number of particles in the probe. We establish this by computing the quantum Fisher information (QFI) which is a lower bound on the root mean square error occurred during parameter estimation. Although we analytically prove the optimality of the symmetric product probe state in ITDM, entangled probe states produce a higher QFI than optimal product probes without enhancing scaling, highlighting the non-essentiality of entanglement. For phase estimation, we propose a single-qubit measurement on the control qubit that accomplishes near-optimal Fisher information and eventually reaches Heisenberg scaling. Our findings reveal the best orientation of product probe states in every pertinent situation, emphasizing its independence from the parameter to be estimated in the limiting case. Furthermore, we illustrate the benefits of ITDM in noisy metrology, outperforming existing techniques in some situations.

Related papers

• 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)
• Finding the optimal probe state for multiparameter quantum metrology using conic programming [61.98670278625053]
  We present a conic programming framework that allows us to determine the optimal probe state for the corresponding precision bounds. We also apply our theory to analyze the canonical field sensing problem using entangled quantum probe states.
  arXiv  Detail & Related papers  (2024-01-11T12:47:29Z)
• Quantum metrology in the finite-sample regime [0.6299766708197883]
  In quantum metrology, the ultimate precision of estimating an unknown parameter is often stated in terms of the Cram'er-Rao bound. We propose to quantify the quality of a protocol by the probability of obtaining an estimate with a given accuracy.
  arXiv  Detail & Related papers  (2023-07-12T18:00:04Z)
• Quantum multiparameter estimation with graph states [6.152619905686453]
  In the SU(2) dynamics, it is especially significant to achieve a simultaneous optimal multi parameter estimation. We propose a simultaneous multi parameter estimation scheme that investigates evolution in SU(N) dynamics. We prove that the graph state is the optimal state of quantum metrology, a set of optimal measurement basic can be found, and the precision limit of multi parameter estimation can attain the quantum Cram'er-Rao bound.
  arXiv  Detail & Related papers  (2023-06-05T00:50:24Z)
• Real-time adaptive estimation of decoherence timescales for a single qubit [2.6938732235832044]
  Characterising the time over which quantum coherence survives is critical for any implementation of quantum bits, memories and sensors. We present an adaptive multi- parameter approach, based on a simple analytical update rule, to estimate the key decoherence in real time. A further speed-up of a factor $sim 2$ can be realised by performing our optimisation with respect to sensitivity as opposed to variance.
  arXiv  Detail & Related papers  (2022-10-12T11:28:23Z)
• 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)
• Exponential precision by reaching a quantum critical point [0.0]
  We report a protocol that is capable of surpassing the quadratic scaling, and yields an exponential advantage. The exponential advantage stems from the breakdown of the adiabatic condition close to a critical point. Our findings unveil a novel quantum metrological protocol whose precision scaling goes beyond the paradigmatic Heisenberg limit.
  arXiv  Detail & Related papers  (2021-12-21T14:46:33Z)
• Bosonic field digitization for quantum computers [62.997667081978825]
  We address the representation of lattice bosonic fields in a discretized field amplitude basis. We develop methods to predict error scaling and present efficient qubit implementation strategies.
  arXiv  Detail & Related papers  (2021-08-24T15:30:04Z)
• 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)
• Information Geometric Aspects of Probability Paths with Minimum Entropy Production for Quantum State Evolution [0.0]
  We show a correspondence between a faster transfer and a higher rate of entropy production. We conclude that higher entropic speed is associated with lower entropic efficiency within the context of quantum state transfer.
  arXiv  Detail & Related papers  (2020-07-06T13:16:28Z)
• Quantum probes for universal gravity corrections [62.997667081978825]
  We review the concept of minimum length and show how it induces a perturbative term appearing in the Hamiltonian of any quantum system. We evaluate the Quantum Fisher Information in order to find the ultimate bounds to the precision of any estimation procedure. Our results show that quantum probes are convenient resources, providing potential enhancement in precision.
  arXiv  Detail & Related papers  (2020-02-13T19:35:07Z)
• 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.