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Related papers: Time-adaptive phase estimation

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Estimates of noise channels for quantum gates are required for most error mitigation techniques and are desirable for informing quantum error correction decoders. These estimates can be obtained by resource-intensive off-line…

Quantum Physics · Physics 2025-07-01 Lucas Daguerre , Mohan Sarovar

Accurate uncertainty estimates are important in sequential model-based decision-making tasks such as Bayesian optimization. However, these estimates can be imperfect if the data violates assumptions made by the model (e.g., Gaussianity).…

Machine Learning · Computer Science 2024-06-27 Shachi Deshpande , Charles Marx , Volodymyr Kuleshov

The quantum-phase-estimation algorithm (QPEA) is widely used to find estimates of unknown phases. The original algorithm relied on an input state in a uniform superposition of all possible bit strings. However, it is known that other input…

Quantum Physics · Physics 2025-05-05 Joseph G. Smith , Crispin H. W. Barnes , David R. M. Arvidsson-Shukur

In this work we demonstrate the use of adapted classical phase retrieval algorithms to perform control-free quantum phase estimation. We eliminate the costly controlled time evolution and Hadamard test commonly required to access the…

Various phase concepts may be treated as special cases of the maximum likelihood estimation. For example the discrete Fourier estimation that actually coincides with the operational phase of Noh, Fouge`res and Mandel is obtained for…

Quantum Physics · Physics 2009-10-31 Jaroslav Rehacek , Zdenek Hradil , Michael Zawisky , Saverio Pascazio , Helmut Rauch , Jan Perina

Many quantum algorithms rely on the measurement of complex quantum amplitudes. Standard approaches to obtain the phase information, such as the Hadamard test, give rise to large overheads due to the need for global controlled-unitary…

Quantum Physics · Physics 2024-05-29 Yilun Yang , Arthur Christianen , Mari Carmen Bañuls , Dominik S. Wild , J. Ignacio Cirac

Unwanted interaction between a quantum system and its fluctuating environment leads to decoherence and is the primary obstacle to establishing a scalable quantum information processing architecture. Strategies such as environmental and…

Quantum phase estimation is a core task in quantum technologies ranging from metrology to quantum computing, where it appears as a key subroutine in various algorithms. Here, we quantitatively connect the performance of phase estimation…

Quantum Physics · Physics 2026-05-11 Felix Ahnefeld , Thomas Theurer , Martin B. Plenio

Quantum sensors can potentially achieve the Heisenberg limit of sensitivity over a large dynamic range using quantum algorithms. The adaptive phase estimation algorithm (PEA) is one example that was proven to achieve such high sensitivities…

A generic qubit unitary operator affected by quantum noise is duplicated and inserted in a coherently superposed channel, superposing two paths offered to a probe qubit across the noisy unitary, and driven by a control qubit. A…

Quantum Physics · Physics 2021-10-14 Francois Chapeau-Blondeau

Single-spin quantum sensors, for example based on nitrogen-vacancy centres in diamond, provide nanoscale mapping of magnetic fields. In applications where the magnetic field may be changing rapidly, total sensing time is crucial and must be…

Quantum Physics · Physics 2021-05-26 K. Craigie , E. M. Gauger , Y. Altmann , C. Bonato

Optimal designs minimize the number of experimental runs (samples) needed to accurately estimate model parameters, resulting in algorithms that, for instance, efficiently minimize parameter estimate variance. Governed by knowledge of past…

Methodology · Statistics 2023-02-03 Nicholas W. Barendregt , Emily G. Webb , Zachary P. Kilpatrick

We present a general approach to error detection of bosonic quantum error-correction codes via an adaptive quantum phase estimation algorithm assisted by a single ancilla qubit. The approach is applicable to a broad class of bosonic codes…

Quantum Physics · Physics 2025-10-08 Yuan-De Jin , Shi-Yu Zhang , Ulrik L. Andersen , Wen-Long Ma

We consider how to characterize the dynamics of a quantum system from a restricted set of initial states and measurements using Bayesian analysis. Previous work has shown that Hamiltonian systems can be well estimated from analysis of noisy…

Quantum Physics · Physics 2014-03-04 S. G. Schirmer , D. K. L. Oi

Using a circuit QED device, we present a theoretical study of real-time quantum state estimation via quantum Bayesian approach. Suitable conditions under which the Bayesian approach can accurately update the density matrix of the qubit are…

Quantum Physics · Physics 2018-01-24 Yang Yang , Beili Gong , Wei Cui

Designing high-precision and efficient schemes is of crucial importance for quantum parameter estimation in practice. The estimation scheme based on continuous quantum measurement is one possible type of this, which looks also the most…

Quantum Physics · Physics 2019-03-12 Cheng Zhang , Kai Zhou , Wei Feng , Xin-Qi Li

Coherent ensembles of $N$ qubits present an advantage in quantum phase estimation over separable mixtures, but coherence decay due to classical phase diffusion reduces overall precision. In some contexts, the strength of diffusion may be…

Quantum Physics · Physics 2013-07-02 Sergey I. Knysh , Gabriel A. Durkin

Quantum compilation is the problem of translating an input quantum circuit into the most efficient equivalent of itself, taking into account the characteristics of the device that will execute the computation. Compilation strategies are…

Quantum Physics · Physics 2022-05-24 Davide Ferrari , Michele Amoretti

We study numerically the effects of static imperfections and residual couplings between qubits for the quantum phase estimation algorithm with two qubits. We show that the success probability of the algorithm is affected significantly more…

Quantum Physics · Physics 2009-11-13 Ignacio Garcia-Mata , Dima L. Shepelyansky

We present a simple formalism describing evolution of a qubit in the process of its measurement in a circuit QED setup. When a phase-sensitive amplifier is used, the evolution depends on only one output quadrature, and the formalism is the…

Quantum Physics · Physics 2012-05-11 Alexander N. Korotkov