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Related papers: Decoherence-Free Subspaces in Quantum Key Distribu…

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For a practical quantum computer to operate, it will be essential to properly manage decoherence. One important technique for doing this is the use of "decoherence-free subspaces" (DFSs), which have recently been demonstrated. Here we…

Quantum Physics · Physics 2009-11-07 Masoud Mohseni , Jeffrey S. Lundeen , Kevin J. Resch , Aephraim M. Steinberg

We propose a new coherent state quantum key distribution protocol that eliminates the need to randomly switch between measurement bases. This protocol provides significantly higher secret key rates with increased bandwidths than previous…

We develop a general theory for quantum key distribution (QKD) in both the forward error correction and the reverse error correction cases when the QKD system is equipped with phase-randomized coherent light with arbitrary number of decoy…

Quantum Physics · Physics 2009-11-13 Masahito Hayashi

A scheme to implement a quantum computer subjected to decoherence and governed by an untunable qubit-qubit interaction is presented. By concatenating dynamical decoupling through bang-bang (BB) pulse with decoherence-free subspaces (DFSs)…

Quantum Physics · Physics 2007-05-23 Yong Zhang , Zheng-Wei Zhou , Bo Yu , Guang-Can Guo

Quantum key distribution (QKD) offers information-theoretic security based on the fundamental laws of physics. However, device imperfections, such as those in active modulators, may introduce side-channel leakage, thus compromising…

Quantum Physics · Physics 2023-05-10 Chengqiu Hu , Wenyuan Wang , Kai-Sum Chan , Zhenghan Yuan , Hoi-Kwong Lo

A new approach to quantum cryptography to be called KCQ, keyed communication in quantum noise, is developed on the basis of quantum detection and communication theory for classical information transmission. By the use of a shared secret key…

Quantum Physics · Physics 2007-05-23 Horace P. Yuen

The notion of symmetry is shown to be at the heart of all error correction/avoidance strategies for preserving quantum coherence of an open quantum system S e.g., a quantum computer. The existence of a non-trivial group of symmetries of the…

Quantum Physics · Physics 2007-05-23 P. Zanardi

Secret communication over public channels is one of the central pillars of a modern information society. Using quantum key distribution this is achieved without relying on the hardness of mathematical problems which might be compromised by…

Quantum key distribution (QKD) provides secure keys resistant to code-breaking quantum computers. As headed towards commercial application, it is crucial to guarantee the practical security of QKD systems. However, the difficulty of…

Quantum Physics · Physics 2018-05-14 Zhengyu Li , Yi-Chen Zhang , Hong Guo

We show how to use decoherence-free subspaces over collective-noise quantum channels to convey classical information in perfect secrecy. We argue that codes defined over decoherence-free subspaces are codes for quantum wiretap channels in…

Quantum Physics · Physics 2012-04-19 Elloá B. Guedes , Francisco M. de Assis

We propose a fully passive twin-field quantum key distribution (QKD) setup where basis choice, decoy-state preparation and encoding are all implemented entirely by post-processing without any active modulation. Our protocol can remove the…

Quantum Physics · Physics 2026-03-25 Wenyuan Wang , Rong Wang , H. F. Chau , Hoi-Kwong Lo

We apply the techniques introduced in [Kraus et. al., Phys. Rev. Lett. 95, 080501, 2005] to prove security of quantum key distribution (QKD) schemes using two-way classical post-processing as well as QKD schemes based on weak coherent…

Quantum Physics · Physics 2011-11-09 Barbara Kraus , Cyril Branciard , Renato Renner

We consider how randomness can be made to play a useful role in quantum information processing - in particular, for decoherence control and the implementation of quantum algorithms. For a two-level system in which the decoherence channel is…

Quantum Physics · Physics 2007-05-23 Chiu Fan Lee , Neil F. Johnson

Side-channel attacks currently constitute the main challenge for quantum key distribution (QKD) to bridge theory with practice. So far two main approaches have been introduced to address this problem, (full) device-independent QKD and…

The construction of large, coherent quantum systems necessary for quantum computation remains an entreating but elusive goal, due to the ubiquitous nature of decoherence. Recent progress in quantum error correction schemes have given new…

Quantum Physics · Physics 2008-02-03 Isaac L. Chuang , Yoshihisa Yamamoto

We show the unconditional security of decoy-state method quantum cryptography with whatever intensity error pattern provided that the error is not too large. Our result immediately applies to the existing experimental data. Our result is…

Quantum Physics · Physics 2013-05-29 Xiang-Bin Wang , Cheng-Zhi Peng , Jun Zhang , Jian-Wei Pan

In this work, we present an experimental deployment of a new design for combined quantum key distribution (QKD) and post-quantum cryptography (PQC). Novel to our system is the dynamic obfuscation of the QKD-PQC sequence of operations, the…

Quantum Physics · Physics 2026-02-20 Anju Rani , Xiaoyu Ai , Aman Gupta , Ravi Singh Adhikari , Robert Malaney

Quantum computers must be able to function in the presence of decoherence. The simplest strategy for decoherence reduction is dynamical decoupling (DD), which requires no encoding overhead and works by converting quantum gates into…

Quantum Physics · Physics 2018-12-05 Bibek Pokharel , Namit Anand , Benjamin Fortman , Daniel Lidar

Decoy states have been proven to be a very useful method for significantly enhancing the performance of quantum key distribution systems with practical light sources. While active modulation of the intensity of the laser pulses is an…

Quantum Physics · Physics 2011-02-17 Marcos Curty , Xiongfeng Ma , Bing Qi , Tobias Moroder

We present a general theorem for the efficient verification of the lower bound of single-photon transmittance. We show how to do decoy-state quantum key distribution efficiently with large random errors in the intensity control. In our…

Quantum Physics · Physics 2009-11-13 X. B. Wang