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Related papers: Bayesian estimation of one-parameter qubit gates

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We propose an adaptive, two steps strategy, for the estimation of mixed qubit states. We show that the strategy is optimal in a local minimax sense for the trace norm distance as well as other locally quadratic figures of merit. Local…

Quantum Physics · Physics 2011-06-23 Madalin Guta , Bas Janssens , Jonas Kahn

We present a protocol to perform self-stabilizing measurements on noisy qubits. We employ rapid purification in a rotating frame whose frequency is estimated and periodically updated via a Bayesian estimation scheme. The Bayesian estimation…

Quantum Physics · Physics 2014-05-30 Sai Vinjanampathy

We show that it is possible to reduce the number of two-qubit gates needed for the construction of an arbitrary controlled-unitary transformation by up to two times using a tunable controlled-phase gate. On the platform of linear optics,…

Quantum Physics · Physics 2015-04-22 Karel Lemr , Karol Bartkiewicz , Antonín Černoch , Miloslav Dušek , Jan Soubusta

Quantum process tomography of each directly implementable quantum gate used in the IBM quantum processors is performed to compute gate error in order to check viability of complex quantum operations in the superconductivity-based quantum…

Quantum Physics · Physics 2022-06-07 Abhishek Shukla , Mitali Sisodia , Anirban Pathak

Quantum phase estimation (QPE) serves as a building block of many different quantum algorithms and finds important applications in computational chemistry problems. Despite the rapid development of quantum hardware, experimental…

Quantum Physics · Physics 2024-03-01 Kentaro Yamamoto , Samuel Duffield , Yuta Kikuchi , David Muñoz Ramo

Quantum approximate optimization algorithm (QAOA) aims to solve discrete optimization problems by sampling bitstrings using a parameterized quantum circuit. The circuit parameters (angles) are optimized in the way that minimizes the cost…

Quantum Physics · Physics 2023-11-29 A. Yu. Chernyavskiy , B. I. Bantysh , Yu. I. Bogdanov

In this paper, we derive optimized measurement-free protocols for quantum error correction and the implementation of a universal gate set optimized for an error model that is noise biased . The noise bias is adapted for neutral atom…

Variational quantum circuits characterise the state of a quantum system through the use of parameters that are optimised using classical optimisation procedures that typically rely on gradient information. The circuit-execution complexity…

Quantum Physics · Physics 2023-07-28 Sayantan Pramanik , Chaitanya Murti , M Girish Chandra

Starting with the basic control system model often employed in NMR pulse design, we derive more realistic control system models taking into account effects such as off-resonant excitation for systems with fixed inter-qubit coupling…

Quantum Physics · Physics 2009-10-01 Sonia Schirmer

This paper explores the effect of three-dimensional rotations on two-qubit Bell states and proposes a Bayesian method for the estimation of the parameters of the rotation. We use a particle filter to estimate the parameters of the rotation…

Quantum Physics · Physics 2023-04-13 Luke Anastassiou , Jason F. Ralph , Simon Maskell , Pieter Kok

The success probability of a quantum algorithm constructed from noisy quantum gates cannot be accurately predicted from single parameter metrics that compare noisy and ideal gates. We illustrate this concept by examining a system with…

Quantum Physics · Physics 2019-03-27 Daniel C. Murphy , Kenneth R. Brown

The problems of optimally estimating a phase, a direction, and the orientation of a Cartesian frame (or trihedron) with general pure states are addressed. Special emphasis is put on estimation schemes that allow for inconclusive answers or…

Quantum Physics · Physics 2013-08-09 B. Gendra , E. Ronco-Bonvehi , J. Calsamiglia , R. Muñoz-Tapia , E. Bagan

We present BAE, a problem-tailored and noise-aware Bayesian algorithm for quantum amplitude estimation. In a fault tolerant scenario, BAE is capable of saturating the Heisenberg limit; if device noise is present, BAE can dynamically…

Quantum Physics · Physics 2025-09-17 Alexandra Ramôa , Luis Paulo Santos

Previous work on sensitivity analysis in Bayesian networks has focused on single parameters, where the goal is to understand the sensitivity of queries to single parameter changes, and to identify single parameter changes that would enforce…

Artificial Intelligence · Computer Science 2012-07-19 Hei Chan , Adnan Darwiche

Quantum multiparameter estimation offers a framework for the simultaneous estimation of multiple parameters, pertaining to possibly noncommutating observables. While the optimal probe for estimating a single unitary phase is well understood…

Quantum Physics · Physics 2025-07-08 Ritopriyo Pal , Priya Ghosh , Ahana Ghoshal , Ujjwal Sen

Gaussian states are of increasing interest in the estimation of physical parameters because they are easy to prepare and manipulate in experiments. In this article, we derive formulae for the optimal estimation of parameters using two- and…

Quantum Physics · Physics 2015-07-16 Dominik Šafránek , Antony R. Lee , Ivette Fuentes

Unitarity randomized benchmarking (URB) is an experimental procedure for estimating the coherence of implemented quantum gates independently of state preparation and measurement errors. These estimates of the coherence are measured by the…

Quantum Physics · Physics 2019-01-17 Bas Dirkse , Jonas Helsen , Stephanie Wehner

Sampling from the output distribution of chaotic quantum evolutions, and of pseudo-random universal quantum circuits in particular, has been proposed as a prominent milestone for near-term quantum supremacy. The same paper notes that…

Quantum Physics · Physics 2017-08-08 Sergio Boixo , Vadim N. Smelyanskiy , Hartmut Neven

Bayesian optimization is a class of global optimization techniques. In Bayesian optimization, the underlying objective function is modeled as a realization of a Gaussian process. Although the Gaussian process assumption implies a random…

Statistics Theory · Mathematics 2023-05-08 Rui Tuo , Wenjia Wang

To employ a quantum device, the performance of the quantum gates in the device needs to be evaluated first. Since the dimensionality of a quantum gate grows exponentially with the number of qubits, evaluating the performance of a quantum…

Quantum Physics · Physics 2022-02-14 Maolin Luo , Xiaoqian Zhang , Xiaoqi Zhou