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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…

Implementing fast and high-fidelity quantum operations using open-loop quantum optimal control relies on having an accurate model of the quantum dynamics. Any deviations between this model and the complete dynamics of the device, such as…

Quantum Physics · Physics 2024-10-31 Elie Genois , Noah J. Stevenson , Noah Goss , Irfan Siddiqi , Alexandre Blais

The unique features of quantum theory offer a powerful new paradigm for information processing. Translating these mathematical abstractions into useful algorithms and applications requires quantum systems with significant complexity and…

Quantum Physics · Physics 2021-04-13 Atharv Joshi , Kyungjoo Noh , Yvonne Y. Gao

Quantum sensors outperform their classical counterparts in their estimation precision, given the same amount of resources. So far, quantum-enhanced sensitivity has been achieved by exploiting the superposition principle. This enhancement…

Quantum Physics · Physics 2022-10-05 Victor Montenegro , Gareth Siôn Jones , Sougato Bose , Abolfazl Bayat

The measurement of the parity of two qubits is a primitive of quantum computing that allows creating deterministic entanglement. In the field of circuit quantum electrodynamics, a scheme to achieve parity measurement of two superconducting…

Quantum Physics · Physics 2012-05-10 Jing Yan Haw , Yimin Wang , Valerio Scarani

It is vital to minimise the impact of errors for near-future quantum devices that will lack the resources for full fault tolerance. Two quantum error mitigation (QEM) techniques have been introduced recently, namely error extrapolation…

Quantum Physics · Physics 2018-08-01 Suguru Endo , Simon C. Benjamin , Ying Li

In quantum information processing quantum operations are often processed alongside measurements which result in classical data. Due to the information gain of classical measurement outputs non-unitary dynamical processes can take place on…

Multiqubit gates that involve three or more qubits are usually thought to be of little significance for fault-tolerant quantum error correction because single gate faults can lead to errors of high Pauli weight. However, recent works have…

A reliable method for characterizing quantum operations that is suitable for improving and validating their accuracies is indispensable for realizing a practical quantum computer. Known methods are still not sufficient because they lack…

Quantum Physics · Physics 2021-06-25 Takanori Sugiyama , Shinpei Imori , Fuyuhiko Tanaka

How well can multiple incompatible observables be implemented by a single measurement? This is a fundamental problem in quantum mechanics with wide implications for the performance optimization of numerous tasks in quantum information…

Quantum Physics · Physics 2024-10-10 Hongzhen Chen , Lingna Wang , Haidong Yuan

We propose a quantum device that can approximate any projective measurement on a qubit. The desired measurement basis is selected by the quantum state of a "program register". The device is optimized with respect to maximal average fidelity…

Quantum Physics · Physics 2009-11-07 Jaromir Fiurasek , Miloslav Dusek , Radim Filip

Quantum metrology research promises approaches to build new sensors that achieve the ultimate level of precision measurement and perform fundamentally better than modern sensors. Practical schemes that tolerate realistic fabrication…

As quantum devices continue to scale, distributed quantum computing emerges as a promising strategy for executing large-scale tasks across modular quantum processors. A central challenge in this paradigm is verifying the correctness of…

High-fidelity qubit readout is a fundamental requirement for practical quantum computing systems. In this work, we investigate methods to enhance the measurement fidelity of flux qubits via a quantum flux parametron-mediated readout scheme.…

Quantum Physics · Physics 2026-03-27 Yanjun Ji , Susanna Kirchhoff , Frank K. Wilhelm

Qubit-resolved operations and measurements are required for most current quantum information processing schemes. However, these operations can be experimentally costly due to the need for local addressing, demanding significant classical…

Quantum Physics · Physics 2026-05-26 Liang Mao , Yifei Wang , Yingfei Gu , Chengshu Li

Quantum fidelity is a measure to quantify the closeness of two quantum states. In an operational sense, it is defined as the minimal overlap between the probability distributions of measurement outcomes and the minimum is taken over all…

Quantum Physics · Physics 2019-07-24 Changhun Oh , Changhyoup Lee , Leonardo Banchi , Su-Yong Lee , Carsten Rockstuhl , Hyunseok Jeong

While the on-chip processing power in circuit QED devices is growing rapidly, an open challenge is to establish high-fidelity quantum links between qubits on different chips. Here, we show entanglement between transmon qubits on different…

Quantum Physics · Physics 2018-02-21 C. Dickel , J. J. Wesdorp , N. K. Langford , S. Peiter , R. Sagastizabal , A. Bruno , B. Criger , F. Motzoi , L. DiCarlo

Quantum measurements on a two-level system can have more than two independent outcomes, and in this case, the measurement cannot be projective. Measurements of this general type are essential to an operational approach to quantum theory,…

Mid-circuit measurements (MCMs) are critical components of the quantum error correction protocols expected to enable utility-scale quantum computing. MCMs can be modeled by quantum instruments (a type of quantum operation or process), which…

The accurate estimation of observables is a crucial task in quantum computing. Recent advances have highlighted the need for (a) specialized protocols for qudit-based devices, that include (b) error-aware strategies. Here, we present…