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We present an experimental method to detect lower bounds to the quantum capacity of two-qubit communication channels. We consider an implementation with polarisation degrees of freedom of two photons and report on the efficiency of such a…

We review in a unified way a recently proposed method to detect properties of unknown quantum channels and lower bounds to quantum capacities, without resorting to full quantum process tomography. The method is based on the preparation of a…

Quantum Physics · Physics 2017-12-19 Chiara Macchiavello , Massimiliano F. Sacchi

We propose a method to detect lower bounds to quantum capacities of a noisy quantum communication channel by means of few measurements. The method is easily implementable and does not require any knowledge about the channel. We test its…

Quantum Physics · Physics 2016-04-12 Chiara Macchiavello , Massimiliano F. Sacchi

We present an effcient experimental procedure that certifies non vanishing quantum capacities for qubit noisy channels. Our method is based on the use of a fixed bipartite entangled state, where the system qubit is sent to the channel…

We study information transmission over a fully correlated amplitude damping channel acting on two qubits. We derive the single-shot classical channel capacity and show that entanglement is needed to achieve the channel best performance. We…

Quantum Physics · Physics 2013-11-01 A. D'Arrigo , G. Benenti , G. Falci , C. Macchiavello

We present a method to detect lower bounds to the classical capacity of quantum communication channels by means of few local measurements (i.e. without complete process tomography), reconstruction of sets of conditional probabilities, and…

Quantum Physics · Physics 2019-08-30 Chiara Macchiavello , Massimiliano F. Sacchi

Determining whether a noisy quantum channel can be used to reliably transmit quantum information at a non-zero rate is a challenging problem in quantum information theory. This is because it requires computation of the channel's coherent…

Quantum Physics · Physics 2024-10-24 Satvik Singh , Nilanjana Datta

We study the four well-known capacities of a two-parameter family of qubit Pauli channels. These are the channels which are covariant under the SO(2) group and contain the depolarizing channel as a special case. We find exact expressions…

Quantum Physics · Physics 2023-09-01 Abbas Poshtvan , Vahid Karimipour

Quantum process tomography, the standard procedure to characterize any quantum channel in nature, is affected by a circular argument: in order to characterize the channel, the tomographic preparation and measurement need in turn to be…

Quantum Physics · Physics 2016-06-13 Michele Dall'Arno , Sarah Brandsen , Francesco Buscemi

The quantum analog of the classical erasure channel provides a simple example of a channel whose asymptotic capacity for faithful transmission of intact quantum states, with and without the assistance of a two-way classical side channel,…

Quantum Physics · Physics 2008-11-26 Charles H. Bennett , David P. DiVincenzo , John A. Smolin

Capacity of dense coding via correlated noisy channel is greater than that in uncorrelated noisy channel. It is shown that weak measurement and reversal measurement can make further effort to improve quantum dense coding capacity in…

Quantum Physics · Physics 2021-12-21 Jin-Kai Li , Kai Xu , Guo-Feng Zhang

We determine both the quantum and the private capacities of low-noise quantum channels to leading orders in the channel's distance to the perfect channel. It has been an open problem for more than 20 years to determine the capacities of…

Quantum Physics · Physics 2023-12-06 Felix Leditzky , Debbie Leung , Graeme Smith

We demonstrate experimentally the possibility of efficiently detecting properties of quantum channels and quantum gates. The optimal detection scheme is first achieved for non entanglement breaking channels of the depolarizing form and is…

We present a method to detect properties of quantum channels, assuming that some a priori information about the form of the channel is available. The method is based on a correspondence with entanglement detection methods for multipartite…

Quantum Physics · Physics 2013-11-13 C. Macchiavello , M. Rossi

Quantum communication channels and quantum memories are the fundamental building blocks of large-scale quantum communication networks. Estimating their capacity to transmit and store quantum information is crucial in order to assess the…

Quantum Physics · Physics 2022-12-01 Ya-Dong Wu , Giulio Chiribella

We investigate the quantum capacity of noisy quantum channels which can be represented by coupling a system to an effectively small environment. A capacity formula is derived for all cases where both system and environment are…

Quantum Physics · Physics 2009-11-13 Michael M. Wolf , David Perez-Garcia

One of the main figures of merit for quantum memories and quantum communication devices is their quantum capacity. It has been studied for arbitrary kinds of quantum channels, but its practical estimation has so far been limited to devices…

Quantum Physics · Physics 2018-05-16 Corsin Pfister , M. Adriaan Rol , Atul Mantri , Marco Tomamichel , Stephanie Wehner

The quantum capacity of a memoryless channel is often used as a single figure of merit to characterize its ability to transmit quantum information coherently. The capacity determines the maximal rate at which we can code reliably over…

Quantum Physics · Physics 2016-05-10 Marco Tomamichel , Mario Berta , Joseph M. Renes

We show an experimental procedure to certify the classical capacity for noisy qubit channels. The method makes use of a fixed bipartite entangled state, where the system qubit is sent to the channel input and the set of local measurements…

The primary objective of quantum Shannon theory is to evaluate the capacity of quantum channels. In spite of the existence of rigorous coding theorems that quantify the transmission of information through quantum channels, superadditivity…

Quantum Physics · Physics 2024-01-17 Rajiuddin Sk , Prasanta K. Panigrahi
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