The Experts below are selected from a list of 32535 Experts worldwide ranked by ideXlab platform
Berry Schoenmakers - One of the best experts on this subject based on the ideXlab platform.
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Generic Security Proof of Quantum Key Exchange using Squeezed States. (arXiv:quant-ph/0508072v1 CROSS LISTED)
2018Co-Authors: Karin Poels, Pim Tuyls, Berry SchoenmakersAbstract:Recently, a Quantum Key Exchange protocol that uses squeezed states was presented by Gottesman and Preskill. In this paper we give a generic security proof for this protocol. The method used for this generic security proof is based on recent work by Christiandl, Renner and Ekert.
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Generic Security Proof of Quantum Key Exchange using Squeezed States
Proceedings. International Symposium on Information Theory 2005. ISIT 2005., 2005Co-Authors: Karin Poels, Pim Tuyls, Berry SchoenmakersAbstract:Recently, a Quantum Key Exchange protocol that uses squeezed states was presented by Gottesman and Preskill. In this paper we give a generic security proof for this protocol. The method used for this generic security proof is based on recent work by Christiandl, Renner and Ekert.
Barbara M. Terhal - One of the best experts on this subject based on the ideXlab platform.
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quantum error correction with the toric Gottesman kitaev preskill code
Physical Review A, 2019Co-Authors: Christophe Vuillot, Hamed Asasi, Yang Wang, Leonid P Pryadko, Barbara M. TerhalAbstract:We examine the performance of the single-mode Gottesman-Kitaev-Preskill (GKP) code and its concatenation with the toric code for a noise model of Gaussian shifts, or displacement errors. We show how one can optimize the tracking of errors in repeated noisy error correction for the GKP code. We do this by examining the maximum-likelihood problem for this setting and its mapping onto a 1D Euclidean path-integral modeling a particle in a random cosine potential. We demonstrate the efficiency of a minimum-energy decoding strategy as a proxy for the path integral evaluation. In the second part of this paper, we analyze and numerically assess the concatenation of the GKP code with the toric code. When toric code measurements and GKP error correction measurements are perfect, we find that by using GKP error information the toric code threshold improves from 10% to 14%. When only the GKP error correction measurements are perfect we observe a threshold at 6%. In the more realistic setting when all error information is noisy, we show how to represent the maximum likelihood decoding problem for the toric-GKP code as a 3D compact QED model in the presence of a quenched random gauge field, an extension of the random-plaquette gauge model for the toric code. We present a decoder for this problem which shows the existence of a noise threshold at shift-error standard deviation σ0 ≈ 0.243 for toric code measurements, data errors and GKP ancilla errors. If the errors only come from having imperfect GKP states, then this corresponds to states with just four photons or more. Our last result is a no-go result for linear oscillator codes, encoding oscillators into oscillators. For the Gaussian displacement error model, we prove that encoding corresponds to squeezing the shift errors. This shows that linear oscillator codes are useless for quantum information protection against Gaussian shift errors.
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Generating grid states from Schrödinger-cat states without postselection
Physical Review A, 2018Co-Authors: Daniel Weigand, Barbara M. TerhalAbstract:Grid (or comb) states are an interesting class of bosonic states introduced by Gottesman, Kitaev, and Preskill [D. Gottesman, A. Kitaev, and J. Preskill, Phys. Rev. A 64, 012310 (2001)PLRAAN1050-294710.1103/PhysRevA.64.012310] to encode a qubit into an oscillator. A method to generate or "breed" a grid state from Schrodinger cat states using beam splitters and homodyne measurements is known [H. M. Vasconcelos, L. Sanz, and S. Glancy, Opt. Lett. 35, 3261 (2010)OPLEDP0146-959210.1364/OL.35.003261], but this method requires postselection. In this paper we show how postprocessing of the measurement data can be used to entirely remove the need for postselection, making the scheme much more viable. We bound the asymptotic behavior of the breeding procedure and demonstrate the efficacy of the method numerically.
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a comparative code study for quantum fault tolerance
Quantum Information & Computation, 2009Co-Authors: Andrew W Cross, David P Divincenzo, Barbara M. TerhalAbstract:We study a comprehensive list of quantum codes as candidates for codes used at the physical level in a fault-tolerant code architecture. Using the Aliferis-Gottesman-Preskill (AGP) ex-Rec method we calculate the pseudo-threshold for these codes against depolarizing noise at various levels of overhead. We estimate the logical noise rate as a function of overhead at a physical error rate of p0 = 1 × 10-4. The Bacon-Shor codes and the Golay code are the best performers in our study.
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a comparative code study for quantum fault tolerance
arXiv: Quantum Physics, 2007Co-Authors: Andrew W Cross, David P Divincenzo, Barbara M. TerhalAbstract:We study a comprehensive list of quantum codes as candidates of codes to be used at the bottom, physical, level in a fault-tolerant code architecture. Using the Aliferis-Gottesman-Preskill (AGP) ex-Rec method we calculate the pseudo-threshold for these codes against depolarizing noise at various levels of overhead. We estimate the logical noise rate as a function of overhead at a physical error rate of $p_0=1\times 10^{-4}$. The Bacon-Shor codes and the Golay code are the best performers in our study.
Karin Poels - One of the best experts on this subject based on the ideXlab platform.
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Generic Security Proof of Quantum Key Exchange using Squeezed States. (arXiv:quant-ph/0508072v1 CROSS LISTED)
2018Co-Authors: Karin Poels, Pim Tuyls, Berry SchoenmakersAbstract:Recently, a Quantum Key Exchange protocol that uses squeezed states was presented by Gottesman and Preskill. In this paper we give a generic security proof for this protocol. The method used for this generic security proof is based on recent work by Christiandl, Renner and Ekert.
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Generic Security Proof of Quantum Key Exchange using Squeezed States
Proceedings. International Symposium on Information Theory 2005. ISIT 2005., 2005Co-Authors: Karin Poels, Pim Tuyls, Berry SchoenmakersAbstract:Recently, a Quantum Key Exchange protocol that uses squeezed states was presented by Gottesman and Preskill. In this paper we give a generic security proof for this protocol. The method used for this generic security proof is based on recent work by Christiandl, Renner and Ekert.
Marie-frédérique Lartigue - One of the best experts on this subject based on the ideXlab platform.
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Editorial: Small Non-coding RNAs in Streptococci.
Frontiers in genetics, 2016Co-Authors: Mohamed-amine Zorgani, Emilie Camiade, Roland Quentin, Marie-frédérique LartigueAbstract:The Editorial on the Research Topic : Small Non-coding RNAs in Streptococci Bacterial small RNAs (sRNAs) are post-transcriptional regulators of gene expression and the mechanisms by which this can occur have begun to be understood (Gottesman and Storz, 2011). In pathogenic bacteria, the importance of sRNAs-mediated regulation depends on a fine-tuning of the expression of various virulence genes
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Small Non-coding RNAs in Streptococci
Frontiers in Genetics, 2016Co-Authors: Mohamed-amine Zorgani, Emilie Camiade, Roland Quentin, Marie-frédérique LartigueAbstract:The Editorial on the Research Topic : Small Non-coding RNAs in Streptococci Bacterial small RNAs (sRNAs) are post-transcriptional regulators of gene expression and the mechanisms by which this can occur have begun to be understood (Gottesman and Storz, 2011). In pathogenic bacteria, the importance of sRNAs-mediated regulation depends on a fine-tuning of the expression of various virulence genes
Michael E. Cuffaro - One of the best experts on this subject based on the ideXlab platform.
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On the Significance of the Gottesman-Knill Theorem
The British Journal for the Philosophy of Science, 2017Co-Authors: Michael E. CuffaroAbstract:According to the Gottesman-Knill theorem, quantum algorithms which utilise only the operations belonging to a certain restricted set are efficiently simulable classically. Since some of the operations in this set generate entangled states, it is commonly concluded that entanglement is insufficient to enable quantum computers to outperform classical computers. I argue in this paper that this conclusion is misleading. First, the statement of the theorem (that the particular set of quantum operations in question can be simulated using a classical computer) is, on reflection, already evident when we consider Bell's and related inequalities in the context of a discussion of computational machines. This, in turn, helps us to understand that the appropriate conclusion to draw from the Gottesman-Knill theorem is not that entanglement is insufficient to enable a quantum performance advantage, but rather that if we limit ourselves to the operations referred to in the Gottesman-Knill theorem, we will not have used the resources provided by an entangled quantum system to their full potential.
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Is Entanglement Sufficient to Enable Quantum Speedup
arXiv: Quantum Physics, 2012Co-Authors: Michael E. CuffaroAbstract:According to the Gottesman-Knill theorem, any quantum algorithm utilising operations chosen exclusively from a particular restricted set are efficiently simulable by a classical computer. Since some of these algorithms involve entangled states, it is commonly concluded that entanglement is insufficient to enable quantum speedup. As I explain, however, the operations belonging to this set are precisely those which will never yield a violation of the Bell inequalities. Thus it should be no surprise that entangled quantum states which only undergo operations in this set are efficiently simulable classically. What the Gottesman-Knill theorem shows us is that it is possible to use an entangled state to less than its full potential. Nevertheless, there is a meaningful sense in which entanglement is sufficient for quantum speedup: an entangled quantum state provides sufficient physical resources to enable quantum speedup, whether or not one elects to use these resources fully.
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On the Implications of the Gottesman-Knill Theorem for our Understanding of the Resources Involved in Quantum Speedup
arXiv: Quantum Physics, 2012Co-Authors: Michael E. CuffaroAbstract:According to the Gottesman-Knill theorem, any quantum algorithm or protocol which exclusively utilises the elements of a certain restricted set of quantum operations can be efficiently simulated by classical means. Since some of the algorithms and protocols falling into this category involve entangled states, it is usually concluded that entanglement cannot be sufficient to enable quantum speedup. In this short note I argue that this conclusion is misleading. As I explain, the quantum operations to which the Gottesman-Knill theorem applies are precisely those which will never cause a qubit to take on an orientation, with respect to the other subsystems comprising the total system of which it is a part, that yields a violation of the Bell inequalities. Thus, while it is true that more than entanglement is required to realise quantum computational speedup in the sense that a quantum computer implementing an entangled quantum state must utilise more than the relatively small portion of its state space that is accessible from the Gottesman-Knill group of transformations alone if it is to outperform a classical computer; i.e., while it is the case that one must \emph{use} such a state to its full potential, it is nevertheless the case that if one is asked what \emph{physical resources} suffice to enable one to bring about a quantum performance advantage, then one can legitimately answer that entanglement alone is sufficient for this task.
