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Related papers: Quantum superreplication of states and gates

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This study proposes a new approach to quantum state recovery following measurement. Specifically, we introduce a special operation that transfers the probability amplitude of the quantum state into its orthogonal complement. This operation…

Quantum Physics · Physics 2025-10-03 Taiga Suzuki , Masayuki Ohzeki

An important step in building a quantum computer is calibrating experimentally implemented quantum gates to produce operations that are close to ideal unitaries. The calibration step involves estimating the systematic errors in gates and…

Quantum Physics · Physics 2021-10-22 Shelby Kimmel , Guang Hao Low , Theodore J. Yoder

Quantum metrology is a promising practical use case for quantum technologies, where physical quantities can be measured with unprecedented precision. In lieu of quantum error correction procedures, near term quantum devices are expected to…

Quantum Physics · Physics 2021-12-03 Yingkai Ouyang , Nathan Shettell , Damian Markham

Quantum metrology is an auspicious discipline of quantum information which is currently witnessing a surge of experimental breakthroughs and theoretical developments. The main goal of quantum metrology is to estimate unknown parameters as…

Quantum Physics · Physics 2022-01-06 Nathan Shettell

Operating quantum sensors and quantum computers would make data in the form of quantum states available for purely quantum processing, opening new avenues for studying physical processes and certifying quantum technologies. In this…

It is known that the classical information like strings of bits can be copied. In 1982, Wootters and Zurek proposed the quantum no-cloning principle. No-cloning principle says that it is impossible to make an identical copy of an arbitrary…

Quantum Physics · Physics 2026-05-18 Dafa Li

We introduce a generalized concept of quantum teleportation in the framework of quantum measurement and reversing operation. Our framework makes it possible to find an optimal protocol for quantum teleportation enabling a faithful transfer…

Quantum Physics · Physics 2021-08-09 Seung-Woo Lee , Dong-Gil Im , Yoon-Ho Kim , Hyunchul Nha , M. S. Kim

Quantum sampling, a fundamental subroutine in numerous quantum algorithms, involves encoding a given probability distribution in the amplitudes of a pure state. Given the hefty cost of large-scale quantum storage, we initiate the study of…

Quantum Physics · Physics 2025-06-10 Longyun Chen , Jingcheng Liu , Penghui Yao

We provide a reformulation of finite dimensional quantum theory in the circuit framework in terms of mathematical axioms, and a reconstruction of quantum theory from operational postulates. The mathematical axioms for quantum theory are the…

Quantum Physics · Physics 2011-08-26 Lucien Hardy

The initial state creation is a starting point of many quantum algorithms and usually is considered as a separate subroutine not included into the algorithm itself. There are many algorithms aimed on creation of special class of states. Our…

Quantum Physics · Physics 2025-05-01 Alexander I. Zenchuk , Wentao Qi , Junde Wu

The computational cost of preparing a quantum state can be substantial depending on the structure of data to be encoded. Many quantum algorithms require repeated sampling to find the answer, mandating reconstruction of the same input state…

We consider quantum computing in the k-qubit model where the starting state of a quantum computer consists of k qubits in a pure state and n-k qubits in a maximally mixed state. We ask the following question: is there a general method for…

Quantum Physics · Physics 2007-05-23 Andris Ambainis , Leonard J. Schulman , Umesh Vazirani

Quantum computing can empower machine learning models by enabling kernel machines to leverage quantum kernels for representing similarity measures between data. Quantum kernels are able to capture relationships in the data that are not…

It is shown that any quantum operation that perfectly clones the entanglement of all maximally-entangled qubit pairs cannot preserve separability. This ``entanglement no-cloning'' principle naturally suggests that some approximate cloning…

Quantum Physics · Physics 2009-11-10 Louis-Philippe Lamoureux , Patrick Navez , Jaromir Fiurasek , Nicolas J. Cerf

Perfect Quantum Cloning Machines (QCM) would allow to use quantum nonlocality for arbitrary fast signaling. However perfect QCM cannot exist. We derive a bound on the fidelity of QCM compatible with the no-signaling constraint. This bound…

Quantum Physics · Physics 2009-10-31 Nicolas Gisin

This paper proves the threshold result, which asserts that quantum computation can be made robust against errors and inaccuracies, when the error rate, $\eta$, is smaller than a constant threshold, $\eta_c$. The result holds for a very…

Quantum Physics · Physics 2007-05-23 Dorit Aharonov , Michael Ben-Or

We pose the question whether the asymptotic equivalence between quantum cloning and quantum state estimation, valid at single-copy level, still holds when all the copies are examined jointly. For an N-to-M cloner, we consider the overall…

Quantum Physics · Physics 2014-04-07 Yuxiang Yang , Giulio Chiribella

The distribution of quantum states over long distances is limited by photon loss. Straightforward amplification as in classical telecommunications is not an option in quantum communication because of the no-cloning theorem. This problem…

Quantum Physics · Physics 2011-03-25 Nicolas Sangouard , Christoph Simon , Hugues de Riedmatten , Nicolas Gisin

A family of quantum cloning machines is introduced that produce two approximate copies from a single quantum bit, while the overall input-to-output operation for each copy is a Pauli channel. A no-cloning inequality is derived, describing…

Quantum Physics · Physics 2009-10-31 Nicolas J. Cerf

We introduce a novel technique that enables observation of quantum states without direct measurement, preserving them for reuse. Our method allows multiple quantum states to be observed at different points within a single circuit, one at a…

Quantum Physics · Physics 2025-04-22 Debarshi Kundu , Avimita Chatterjee , Swaroop Ghosh