English
Related papers

Related papers: Programmability of covariant quantum channels

200 papers

qPCF is a paradigmatic quantum programming language that ex- tends PCF with quantum circuits and a quantum co-processor. Quantum circuits are treated as classical data that can be duplicated and manipulated in flexible ways by means of a…

Logic in Computer Science · Computer Science 2018-09-18 Luca Paolini , Mauro Piccolo , Margherita Zorzi

Quantum networks can enable various applications such as distributed quantum computing, long-distance quantum communication, and network-based quantum sensing with unprecedented performances. One of the most important building blocks for a…

Quantum Physics · Physics 2024-05-01 Sheng Zhang , Jixuan Shi , Zhaibin Cui , Ye Wang , Yukai Wu , Luming Duan , Yunfei Pu

We introduce Partially Coherent Direct Sum (PCDS) quantum channels, as a generalization of the already known Direct Sum quantum channels. We derive necessary and sufficient conditions to identify the subset of those maps which are…

Quantum Physics · Physics 2021-07-21 Stefano Chessa , Vittorio Giovannetti

Geometric quantum machine learning uses the symmetries inherent in data to design tailored machine learning tasks with reduced search space dimension. The field has been well-studied recently in an effort to avoid barren plateau issues…

Quantum Physics · Physics 2025-07-14 Zachary P. Bradshaw , Ethan N. Evans , Matthew Cook , Margarite L. LaBorde

Transmitting data reliably over noisy communication channels is one of the most important applications of information theory, and well understood when the channel is accurately modelled by classical physics. However, when quantum effects…

Implementing a qubit quantum computer in continuous-variable systems conventionally requires the engineering of specific interactions according to the encoding basis states. In this work, we present a unified formalism to conduct universal…

Quantum Physics · Physics 2016-09-06 Hoi-Kwan Lau , Martin B. Plenio

In this thesis, we are interested in the limits of quantum communication with and without entanglement, and with and without noise assumptions on the communication setup. When a sender and a receiver are connected by a communication line…

Quantum Physics · Physics 2024-12-31 Paula Belzig

The quantum channel capacity gives the ultimate limit for the rate at which quantum data can be reliably transmitted through a noisy quantum channel. Degradable quantum channels are among the few channels whose quantum capacities are known.…

Quantum Physics · Physics 2011-03-31 Markus Grassl , Zhengfeng Ji , Zhaohui Wei , Bei Zeng

We consider the quantum processor based on a chain of trapped ions to propose an architecture wherein the motional degrees of freedom of trapped ions (position and momentum) could be exploited as the computational Hilbert space. We adopt a…

Quantum simulation uses a well-known quantum system to predict the behavior of another quantum system. Certain limitations in this technique arise, however, when applied to specific problems, as we demonstrate with a theoretical and…

Quantum Physics · Physics 2009-11-13 Kenneth R. Brown , Robert J. Clark , Isaac L. Chuang

Quantum channel capacities are fundamental to quantum information theory. Their definition, however, does not limit the computational resources of sender and receiver. In this work, we initiate the study of computational quantum capacities.…

Quantum Physics · Physics 2026-01-23 Johannes Jakob Meyer , Jacopo Rizzo , Asad Raza , Lorenzo Leone , Sofiene Jerbi , Jens Eisert

Current experiments are taking the first steps toward noise-resilient logical qubits. Crucially, a quantum computer must not merely store information, but also process it. A fault-tolerant computational procedure ensures that errors do not…

Quantum Physics · Physics 2018-11-13 Earl T. Campbell , Barbara M. Terhal , Christophe Vuillot

Construction of explicit quantum circuits follows the notion of the "standard circuit model" introduced in the solid and profound analysis of elementary gates providing quantum computation. Nevertheless the model is not always optimal (e.g.…

Quantum Physics · Physics 2007-05-23 K. Ch. Chatzisavvas , C. Daskaloyannis , C. P. Panos

What resources are universal for quantum computation? In the standard model, a quantum computer consists of a sequence of unitary gates acting coherently on the qubits making up the computer. This paper shows that a very different model…

Quantum Physics · Physics 2009-11-07 Michael A. Nielsen

A pair of quantum channels are said to be incompatible if they cannot be realized as marginals of a single channel. This paper addresses the general structure of the incompatibility of completely positive channels with a fixed quantum input…

Quantum Physics · Physics 2018-04-19 Yui Kuramochi

An examination of the concept of using classical degrees of freedom to drive the evolution of quantum computers is given. Specifically, when externally generated, coherent states of the electromagnetic field are used to drive transitions…

Quantum Physics · Physics 2009-10-31 Jeff P. Barnes , Warren S. Warren

The implementation of a quantum computer requires the realization of a large number of N-qubit unitary operations which represent the possible oracles or which are part of the quantum algorithm. Until now there are no standard ways to…

Quantum Physics · Physics 2009-11-10 Norbert Schuch , Jens Siewert

Quantum computing has quickly emerged as a revolutionary paradigm that holds the potential for greatly enhanced computational capability and algorithmic efficiency, in a wide range of areas. Among the various hardware platforms, neutral…

Quantum Physics · Physics 2026-03-19 Matteo Grotti , Sara Marzella , Gabriella Bettonte , Daniele Ottaviani , Elisa Ercolessi

It is becoming increasingly clear that, if a useful device for quantum computation will ever be built, it will be embodied by a classical computing machine with control over a truly quantum subsystem, this apparatus performing a mixture of…

Programming Languages · Computer Science 2009-11-07 S. Bettelli , L. Serafini , T. Calarco

Quantum computing promises to exploit the laws of quantum mechanics for processing information in ways fundamentally different from today's classical computers, leading to unprecedented efficiency. One-way quantum computation, sometimes…