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Related papers: No-cloning theorem for 2WQC and postselection

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The one-way quantum computer (QCc) is a universal scheme of quantum computation consisting only of one-qubit measurements on a particular entangled multi-qubit state, the cluster state. The computational model underlying the QCc is…

Quantum Physics · Physics 2007-05-23 R. Raussendorf , H. J. Briegel

The cluster state quantum computation is a versatile approach to build a scalable quantum computer. In this thesis we theoretically demonstrate that a one dimensional array of double quantum dots with long spin relaxation time can evolve to…

Strongly Correlated Electrons · Physics 2009-12-14 M. M. Aghili Yajadda

Copying the quantum states is contradictory to classical information processing since the fundamental difference between classical and quantum information is that while classical information can be copied perfectly, quantum information…

Quantum Physics · Physics 2022-01-10 Artyom M. Grigoryan , Sos S. Agaian

The cloning of quantum variables with continuous spectra is analyzed. A universal - or Gaussian - quantum cloning machine is exhibited that copies equally well the states of two conjugate variables such as position and momentum. It also…

Quantum Physics · Physics 2009-10-31 N. J. Cerf , A. Ipe , X. Rottenberg

Rapidly improving gate fidelities for coherent operations mean that errors in state preparation and measurement (SPAM) may become a dominant source of error for fault-tolerant operation of quantum computers. This is particularly acute in…

Quantum Physics · Physics 2023-05-10 Ben Barber , Neil I. Gillespie , J. M. Taylor

Blind Quantum Computation (BQC) is a delegation computing protocol that allows a client to utilize a remote quantum server to implement desired quantum computations while keeping her inputs, outputs, and algorithms private. However, qubit…

Quantum Physics · Physics 2023-03-07 Qiang Zhao , John C. S. Lui

In this letter, first, we investigate the security of a continuous-variable quantum cryptographic scheme with a postselection process against individual beam splitting attack. It is shown that the scheme can be secure in the presence of the…

Quantum Physics · Physics 2009-11-10 Ryo Namiki , Takuya Hirano

1-way quantum finite automata are deterministic and reversible in nature, which greatly reduces its accepting property. In fact the set of languages accepted by 1-way quantum finite automata is a proper subset of regular languages. In this…

Formal Languages and Automata Theory · Computer Science 2015-12-10 Kingshuk Chatterjee , Kumar Sankar Ray

We derive an analytical description for the quantum state preparation using systems of on-off detectors. Our method will apply the true click statistics of such detector systems. In particular, we consider heralded quantum state preparation…

Quantum Physics · Physics 2015-06-19 J. Sperling , W. Vogel , G. S. Agarwal

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

We present a computational circuit which realizes contextually the Tele-UNOT gate and the universal optimal quantum cloning machine (UOQCM). We report the experimental realization of the probabilistic UOQCM with polarization encoded qubits.…

Quantum Physics · Physics 2009-11-10 F. Sciarrino , C. Sias , M. Ricci , F. De Martini

Decoupling theorems have proven useful in various applications in the area of quantum information theory. This thesis builds upon preceding work by Fr\'{e}d\'{e}ric Dupuis [arXiv:1012.6044v1], where a general decoupling theorem is obtained…

Quantum Physics · Physics 2012-07-18 Oleg Szehr

Probabilistic quantum cloning and identifying machines can be constructed via unitary-reduction processes [Duan and Guo, Phys. Rev. Lett. 80, 4999 (1998)]. Given the cloning (identifying) probabilities, we derive an explicit representation…

Quantum Physics · Physics 2009-10-31 Chuan-Wei Zhang , Zi-Yang Wang , Chuan-Feng Li , Guang-Can Guo

We propose several methods for quantum key distribution (QKD) based upon the generation and transmission of random distributions of coherent or squeezed states, and we show that they are are secure against individual eavesdropping attacks.…

Quantum Physics · Physics 2016-09-08 Frédéric Grosshans , Philippe Grangier

Quantum bit commitment (QBC) is insecure in the standard non-relativistic quantum cryptographic framework, essentially because Alice can exploit quantum steering to defer making her commitment. Two assumptions in this framework are that:…

Quantum Physics · Physics 2018-02-15 R. Srikanth

A quantum computer is a hypothetical device in which the laws of quantum mechanics are used to introduce a degree of parallelism into computations and which could therefore significantly improve on the computational speed of a classical…

Quantum Physics · Physics 2007-05-23 P. Blythe , B. Varcoe

The highest current estimates for the amount of noise a quantum computer can tolerate are based on fault-tolerance schemes relying heavily on postselecting on no detected errors. However, there has been no proof that these schemes give even…

Quantum Physics · Physics 2012-06-22 Ben W. Reichardt

We realize the probabilistic cloning and identifying linear independent quantum states of multi-particles system, given prior probability, with universal quantum logic gates using the method of unitary representation. Our result is…

Quantum Physics · Physics 2007-05-23 Chuan-Wei Zhang , Chuan-Feng Li , Guang-Can Guo

In recent years, quantum computers and Shor quantum algorithm have posed a threat to current mainstream asymmetric cryptography methods (e.g. RSA and Elliptic Curve Cryptography (ECC)). Therefore, it is necessary to construct a Post-Quantum…

Cryptography and Security · Computer Science 2024-02-27 Abel C. H. Chen

We identify regimes where post-selection can be used scalably in quantum error correction (QEC) to improve performance. We use statistical mechanical models to analytically quantify the performance and thresholds of post-selected QEC, with…

Quantum Physics · Physics 2025-09-22 Lucas H. English , Dominic J. Williamson , Stephen D. Bartlett