English
Related papers

Related papers: Co-Processors for Quantum Devices

200 papers

We introduce a general scheme for sequential one-way quantum computation where static systems with long-living quantum coherence (memories) interact with moving systems that may possess very short coherence times. Both the generation of the…

Quantum Physics · Physics 2015-05-27 Augusto J. Roncaglia , Leandro Aolita , Alessandro Ferraro , Antonio Acin

Quantum cloning of two identical mixed qubits $\rho \otimes \rho $ is studied. We propose the quantum cloning transformations not only for the triplet (symmetric) states but also for the singlet (antisymmetric) state. We can copy these two…

Quantum Physics · Physics 2007-07-12 H. Fan , B. Y. Liu , K. J. Shi

Using coherent states in optical quantum process tomography is a practically-relevant approach. Here, we develop a framework for complete characterization of quantum-optical processes in terms of normally-ordered moments by using coherent…

Quantum Physics · Physics 2017-04-11 M. Ghalaii , A. T. Rezakhani

Quantum computers process information with the laws of quantum mechanics. Current quantum hardware is noisy, can only store information for a short time, and is limited to a few quantum bits, i.e., qubits, typically arranged in a planar…

A general multi-step N->M probabilistic optimal universal cloning protocol is presented together with the experimental realization of the (1 -> 3) and (2 -> 3) machines. Since the present method exploits the bosonic nature of the photons,…

Quantum Physics · Physics 2007-05-23 L. Masullo , M. Ricci , F. De Martini

The two essential ideas in this paper are, on the one hand, that a considerable amount of the power of quantum computation may be obtained by adding to a classical computer a few specialized quantum modules and, on the other hand, that such…

Quantum Physics · Physics 2021-12-15 R. Vilela Mendes

Quantum compiling, a process that decomposes the quantum algorithm into a series of hardware-compatible commands or elementary gates, is of fundamental importance for quantum computing. We introduce an efficient algorithm based on deep…

Quantum Physics · Physics 2020-10-22 Yuan-Hang Zhang , Pei-Lin Zheng , Yi Zhang , Dong-Ling Deng

The optimal phase covariant cloning machine (PQCM) broadcasts the information associated to an input qubit into a multi-qubit systems, exploiting a partial a-priori knowledge of the input state. This additional a priori information leads to…

Quantum Physics · Physics 2009-11-13 Fabio Sciarrino , Francesco De Martini

The practical application of quantum technologies to chemical problems faces significant challenges, particularly in the treatment of realistic basis sets and the accurate inclusion of electron correlation effects. A direct approach to…

Utility-scale quantum programs contain operations on the order of $>10^{15}$ which must be prepared and piped from a classical co-processor to the control unit of the quantum device. The latency of this process significantly increases with…

Quantum Physics · Physics 2025-07-29 Ioana Moflic , Alan Robertson , Simon J. Devitt , Alexandru Paler

Quantum computing is a promising paradigm based on quantum theory for performing fast computations. Quantum algorithms are expected to surpass their classical counterparts in terms of computational complexity for certain tasks, including…

Quantum computers promise to enhance machine learning for practical applications. Quantum machine learning for real-world data has to handle extensive amounts of high-dimensional data. However, conventional methods for measuring quantum…

Quantum Physics · Physics 2023-02-10 Tobias Haug , Chris N. Self , M. S. Kim

Photons are natural carriers of high-dimensional quantum information, and, in principle, can benefit from higher quantum information capacity and noise-resilience. However, schemes to generate the resources required for high-dimensional…

Quantum Physics · Physics 2021-06-28 Stefano Paesani , Jacob F. F. Bulmer , Alex E. Jones , Raffaele Santagati , Anthony Laing

A universal programmable quantum processor uses program quantum states to apply an arbitrary quantum channel to an input state. We generalize the concept of a finite-dimensional programmable quantum processor to infinite dimension assuming…

Quantum Physics · Physics 2021-07-15 Martina Gschwendtner , Andreas Winter

With the increasing size of quantum processors, sub-modules that constitute the processor hardware will become too large to accurately simulate on a classical computer. Therefore, one would soon have to fabricate and test each new design…

Quantum computing is an emerging technology, promising a paradigm shift in computing, and allowing for speedups in many different problems. However, quantum devices are still in their early stages, most with only a small number qubits. This…

Quantum Physics · Physics 2018-11-09 Adam Kelly

A key problem in quantum computing is finding a viable technological path toward the creation of a scalable quantum computer. One possible approach toward solving part of this problem is distributed computing, which provides an effective…

Quantum Physics · Physics 2007-05-23 Anocha Yimsiriwattana , Samuel J. Lomonaco

Digital quantum simulators are among the most appealing applications of a quantum computer. Here we propose a universal, scalable, and integrated quantum computing platform based on tunable nonlinear electromechanical nano-oscillators. It…

Quantum Physics · Physics 2018-06-20 F. Tacchino , A. Chiesa , M. D. LaHaye , S. Carretta , D. Gerace

In a quantum computer any superposition of inputs evolves unitarily into the corresponding superposition of outputs. It has been recently demonstrated that such computers can dramatically speed up the task of finding factors of large…

Quantum Physics · Physics 2016-09-08 I. Chuang , Raymond Laflamme , P. Shor , W. Zurek

We establish the best possible approximation to a perfect quantum cloning machine which produces two clones out of a single input. We analyze both universal and state-dependent cloners. The maximal fidelity of cloning is shown to be 5/6 for…

Quantum Physics · Physics 2009-10-30 D. Bruss , D. P. DiVincenzo , A. Ekert , C. A. Fuchs , C. Macchiavello , J. A. Smolin