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Related papers: Optimal Quantum Purity Amplification

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We propose using variational quantum algorithms (VQAs) to simulate established quantum algorithms under realistic noise conditions, aiming to surpass the fidelity of theoretical circuits in noisy environments. Focusing on the Quantum…

Quantum amplification is essential for various quantum technologies such as communication and weak-signal detection. However, its practical use is still limited due to inevitable device fragility that brings about distortion in the output…

Quantum Physics · Physics 2016-05-09 Naoki Yamamoto

We study the use of entanglement purification for quantum communication over long distances. For distances much longer than the coherence length of a corresponding noisy quantum channel, the fidelity of transmission is usually so low that…

Quantum Physics · Physics 2008-12-18 W. Dür , H. - J. Briegel , J. I. Cirac , P. Zoller

Linear quantum amplifiers are indispensable tools for quantum technologies, yet their performance is fundamentally limited by quantum noise, precluding any signal-to-noise ratio (SNR) enhancement unless supplemented by post-selection or…

Quantum Physics · Physics 2026-03-13 Ya-Long Ren , Rong-Teng Cao , Sheng-Li Ma , Ren Zhang , Fu-Li Li , Franco Nori , Peng-Bo Li

Quantum enhanced sensing provides a powerful tool for the precise measurement of physical parameters that is applicable in many areas of science and technology. The achievable gain in sensitivity is largely limited by the influence of noise…

Quantum Physics · Physics 2016-12-07 Yu Liu , Zijun Shu , Martin B. Plenio , Jianming Cai

Noise in quantum hardware remains the biggest roadblock for the implementation of quantum computers. To fight the noise in the practical application of near-term quantum computers, instead of relying on quantum error correction which…

Quantum Physics · Physics 2021-10-14 Zhenyu Cai

Quantum state purification is the task of recovering a nearly pure copy of an unknown pure quantum state using multiple noisy copies of the state. This basic task has applications to quantum communication over noisy channels and quantum…

Quantum Physics · Physics 2025-01-22 Andrew M. Childs , Honghao Fu , Debbie Leung , Zhi Li , Maris Ozols , Vedang Vyas

Fighting against noise is crucial for NISQ devices to demonstrate practical quantum applications. In this work, we give a new paradigm of quantum error mitigation based on the vectorization of density matrices. Different from the ideas of…

Quantum Physics · Physics 2024-07-22 Zhong-Xia Shang , Zi-Han Chen , Cai-Sheng Cheng

In the current NISQ (Noisy Intermediate-Scale Quantum) era, simulating and verifying noisy quantum circuits is crucial but faces challenges such as quantum state explosion and complex noise representations, constraining simulation and…

Quantum Physics · Physics 2025-12-12 Mingyu Huang , Ji Guan , Wang Fang , Mingsheng Ying

Quantum error mitigation (QEM) infers noiseless expectation values from noisy variants of a target quantum circuit. Unlike quantum error correction, QEM requires no additional hardware resources and is therefore routinely employed in…

Quantum Physics · Physics 2026-03-04 Raam Uzdin

Designing noisy-resilience quantum algorithms is indispensable for practical applications on Noisy Intermediate-Scale Quantum~(NISQ) devices. Here we propose a quantum approximate optimization algorithm~(QAOA) with a very shallow circuit,…

Quantum Physics · Physics 2021-09-27 Fang-Gang Duan , Dan-Bo Zhang

We establish the optimal quantum teleportation protocol for the realistic scenario when both input state and quantum channel are afflicted by noise. In taking these effects into account higher fidelities are achieved. The optimality of the…

Quantum Physics · Physics 2012-02-03 Bruno G. Taketani , Fernando de Melo , Ruynet L. de Matos Filho

Solving differential equations is one of the most promising applications of quantum computing. Recently we proposed an efficient quantum algorithm for solving one-dimensional Poisson equation avoiding the need to perform quantum arithmetic…

Quantum algorithm involves the manipulation of amplitudes and computational basis, of which manipulating basis is largely a quantum analogue of classical computing that is always a major contributor to the complexity. In order to make full…

We introduce entanglement purification protocols for d-level systems (qudits) with improved efficiency as compared to previous protocols. While we focus on protocols for bipartite systems, we also propose generalizations to multi-partite…

Quantum Physics · Physics 2018-10-17 Jorge Miguel-Ramiro , Wolfgang Dür

We consider entanglement distillation with noisy operations in which quantum measurements that constitute a general quantum operation are particularly noisy. We present a protocol for purifying noisy measurements and show that imperfect…

Quantum Physics · Physics 2025-02-11 Jaemin Kim , Jiyoung Yun , Joonwoo Bae

Quantum systems are inherently open and susceptible to environmental noise, which can have both detrimental and beneficial effects on their dynamics. This phenomenon has been observed in bio-molecular systems, where noise enables novel…

Non-deterministic noiseless amplification of a single mode can circumvent the unique challenges to amplifying a quantum signal, such as the no-cloning theorem, and the minimum noise cost for deterministic quantum state amplification.…

Quantum Physics · Physics 2013-05-31 S. Kocsis , G. Y. Xiang , T. C. Ralph , G. J. Pryde

Learning unknown processes affecting a quantum system reveals underlying physical mechanisms and enables suppression, mitigation, and correction of unwanted effects. Describing a general quantum process requires an exponentially large…

A quantum network is expected to enhance distributed quantum computing and quantum communication over a long distance while providing unconditional security. As quantum entanglement is essential for a quantum network, major issues from…

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