The Experts below are selected from a list of 132 Experts worldwide ranked by ideXlab platform

Gilles Zemor - One of the best experts on this subject based on the ideXlab platform.

  • Quantum Expander Codes
    2015
    Co-Authors: Anthony Leverrier, Jean-pierre Tillich, Gilles Zemor
    Abstract:

    We present an efficient decoding algorithm for constant rate quantum hyper graph-product LDPC Codes which provably corrects adversarial errors of weight proportional to the Code minimum distance, or equivalently to the square-root of the block length. The algorithm runs in time linear in the number of qubits, which makes its performance the strongest to date for linear-time decoding of quantum Codes. The algorithm relies on expanding properties, not of the quantum Code's factor graph directly, but of the factor graph of the original Classical Code it is constructed from.

  • Quantum Expander Codes
    2015 IEEE 56th Annual Symposium on Foundations of Computer Science, 2015
    Co-Authors: Anthony Leverrier, Jean-pierre Tillich, Gilles Zemor
    Abstract:

    We present an efficient decoding algorithm for constant rate quantum hypergraph-product LDPC Codes which provably corrects adversarial errors of weight $\Omega(\sqrt{n})$ for Codes of length $n$. The algorithm runs in time linear in the number of qubits, which makes its performance the strongest to date for linear-time decoding of quantum Codes. The algorithm relies on expanding properties, not of the quantum Code's factor graph directly, but of the factor graph of the original Classical Code it is constructed from.

  • A construction of quantum LDPC Codes from Cayley graphs
    IEEE Transactions on Information Theory, 2013
    Co-Authors: Alain Couvreur, Nicolas Delfosse, Gilles Zemor
    Abstract:

    We study a construction of Quantum LDPC Codes proposed by MacKay, Mitchison and Shokrollahi in the draft [6]. It is based on the Cayley graph of F_2^n together with a set of generators regarded as the columns of the parity-check matrix of a Classical Code. We give a general lower bound on the minimum distance of the quantum Code in O(dn^2) where d is the minimum distance of the Classical Code. When the Classical Code is the [n; 1; n] repetition Code, we are able to compute the exact parameters of the associated quantum Code which are [[2^{n-1}, 2^{n/2}, 2^{n/2-1}]].

  • A Construction of Quantum LDPC Codes From Cayley Graphs
    IEEE Transactions on Information Theory, 2013
    Co-Authors: Alain Couvreur, Nicolas Delfosse, Gilles Zemor
    Abstract:

    We study a construction of quantum LDPC Codes proposed by MacKay, Mitchison, and Shokrollahi. It is based on the Cayley graph of \BBF2n together with a set of generators regarded as the columns of the parity-check matrix of a Classical Code. We give a general lower bound on the minimum distance of the quantum Code in O(dn2) where d is the minimum distance of the Classical Code. This bound is logarithmic in the blocklength 2n of the quantum Code. When the Classical Code is the [n,1,n] repetition Code, we are able to compute the exact parameters of the associated quantum Code which are [[2n, 2[(n+1)/2], 2[(n-1)/2]]].

  • A Construction of Quantum LDPC Codes from Cayley Graphs
    arXiv: Information Theory, 2012
    Co-Authors: Alain Couvreur, Nicolas Delfosse, Gilles Zemor
    Abstract:

    We study a construction of Quantum LDPC Codes proposed by MacKay, Mitchison and Shokrollahi. It is based on the Cayley graph of Fn together with a set of generators regarded as the columns of the parity-check matrix of a Classical Code. We give a general lower bound on the minimum distance of the Quantum Code in $\mathcal{O}(dn^2)$ where d is the minimum distance of the Classical Code. When the Classical Code is the $[n, 1, n]$ repetition Code, we are able to compute the exact parameters of the associated Quantum Code which are $[[2^n, 2^{\frac{n+1}{2}}, 2^{\frac{n-1}{2}}]]$.

Alain Couvreur - One of the best experts on this subject based on the ideXlab platform.

  • A construction of quantum LDPC Codes from Cayley graphs
    IEEE Transactions on Information Theory, 2013
    Co-Authors: Alain Couvreur, Nicolas Delfosse, Gilles Zemor
    Abstract:

    We study a construction of Quantum LDPC Codes proposed by MacKay, Mitchison and Shokrollahi in the draft [6]. It is based on the Cayley graph of F_2^n together with a set of generators regarded as the columns of the parity-check matrix of a Classical Code. We give a general lower bound on the minimum distance of the quantum Code in O(dn^2) where d is the minimum distance of the Classical Code. When the Classical Code is the [n; 1; n] repetition Code, we are able to compute the exact parameters of the associated quantum Code which are [[2^{n-1}, 2^{n/2}, 2^{n/2-1}]].

  • A Construction of Quantum LDPC Codes From Cayley Graphs
    IEEE Transactions on Information Theory, 2013
    Co-Authors: Alain Couvreur, Nicolas Delfosse, Gilles Zemor
    Abstract:

    We study a construction of quantum LDPC Codes proposed by MacKay, Mitchison, and Shokrollahi. It is based on the Cayley graph of \BBF2n together with a set of generators regarded as the columns of the parity-check matrix of a Classical Code. We give a general lower bound on the minimum distance of the quantum Code in O(dn2) where d is the minimum distance of the Classical Code. This bound is logarithmic in the blocklength 2n of the quantum Code. When the Classical Code is the [n,1,n] repetition Code, we are able to compute the exact parameters of the associated quantum Code which are [[2n, 2[(n+1)/2], 2[(n-1)/2]]].

  • A Construction of Quantum LDPC Codes from Cayley Graphs
    arXiv: Information Theory, 2012
    Co-Authors: Alain Couvreur, Nicolas Delfosse, Gilles Zemor
    Abstract:

    We study a construction of Quantum LDPC Codes proposed by MacKay, Mitchison and Shokrollahi. It is based on the Cayley graph of Fn together with a set of generators regarded as the columns of the parity-check matrix of a Classical Code. We give a general lower bound on the minimum distance of the Quantum Code in $\mathcal{O}(dn^2)$ where d is the minimum distance of the Classical Code. When the Classical Code is the $[n, 1, n]$ repetition Code, we are able to compute the exact parameters of the associated Quantum Code which are $[[2^n, 2^{\frac{n+1}{2}}, 2^{\frac{n-1}{2}}]]$.

  • ISIT - A construction of quantum LDPC Codes from Cayley graphs
    2011 IEEE International Symposium on Information Theory Proceedings, 2011
    Co-Authors: Alain Couvreur, Nicolas Delfosse, Gilles Zemor
    Abstract:

    We study a construction of Quantum LDPC Codes proposed by MacKay, Mitchison and Shokrollahi in the draft [6]. It is based on the Cayley graph of F 2 n together with a set of generators regarded as the columns of the parity-check matrix of a Classical Code. We give a general lower bound on the minimum distance of the quantum Code in O(dn2) where d is the minimum distance of the Classical Code. When the Classical Code is the [n, 1, n] repetition Code, we are able to compute the exact parameters of the associated quantum Code which are equation

R. Prasad - One of the best experts on this subject based on the ideXlab platform.

  • A study of pre-equilibrium emission of neutrons in ^93Nb(α, xn) reactions
    The European Physical Journal A, 2007
    Co-Authors: Manoj Kumar Sharma, H. D. Bhardwaj, Pushpendra P. Singh, B. P. Singh, R. Prasad
    Abstract:

    With a view to study the pre-equilibrium emission mechanism in α-induced reactions the excitation functions for ^93Nb(α, n )^96 m Tc, ^93Nb(α, n )^96Tc, ^93Nb(α, 2 n )^95 m Tc, ^93Nb(α, 2 n )^95 g Tc and ^93Nb(α, 3 n )^94Tc reactions have been measured in the energy range threshold to ≈ 10MeV/nucleon using the activation technique. The measured excitation functions have also been compared with theoretical predictions based on the semi-Classical Code, which takes into account compound nucleus as well as pre-equilibrium emission. The analysis of the data indicates significant contribution from pre-equilibrium emission at these energies particularly in the high-energy tail portion of EFs. The effect of the variation of the parameters used in the Code has been studied. The isomeric cross-section ratios have also been measured. It has been observed that the pre-equilibrium fraction increases rapidly with the increase in α-particle bombarding energy.

  • A study of pre-equilibrium emission in some proton- and alpha-induced reactions
    Nuclear Instruments and Methods in Physics Research Section A: Accelerators Spectrometers Detectors and Associated Equipment, 2006
    Co-Authors: Brijesh Singh, Manoj Kumar Sharma, M. M. Musthafa, H. D. Bhardwaj, R. Prasad
    Abstract:

    Abstract Excitation functions (EFs) for a large number of proton- and alpha-induced reactions in the energy range ≈8–60 MeV have been measured employing stacked foil activation technique. The theoretical calculations of the EFs have been carried out using the semi-Classical Code, which includes compound nucleus (CN) and pre-equilibrium (PE) emission into consideration. In general, the theoretical calculations agree well with the experimental data. The PE fraction has also been calculated and found to depend strongly on the energy of the incident particle.

Scott Pakin - One of the best experts on this subject based on the ideXlab platform.

  • targeting Classical Code to a quantum annealer
    Architectural Support for Programming Languages and Operating Systems, 2019
    Co-Authors: Scott Pakin
    Abstract:

    From a compiler's perspective, a quantum annealer represents a fundamentally different hardware target from a CPU, GPU, or other von Neumann architecture. Quantum annealers are special-purpose computers that use quantum effects to heuristically determine the set of Boolean variables that minimize a quadratic pseudo-Boolean function (an NP-hard problem). Natively programming such systems involves supplying them with a vector of function coefficients and receiving a vector of function-minimizing Booleans in return. The contribution of this work is to demonstrate how to compile conventional Code into a minimization problem for solution on a quantum annealer. The resulting Code can run either forward (from inputs to outputs) or backward (from outputs to inputs). We show how this capability can be exploited to simplify the expression and solution of problems in the NP complexity class.

  • ASPLOS - Targeting Classical Code to a Quantum Annealer
    Proceedings of the Twenty-Fourth International Conference on Architectural Support for Programming Languages and Operating Systems, 2019
    Co-Authors: Scott Pakin
    Abstract:

    From a compiler's perspective, a quantum annealer represents a fundamentally different hardware target from a CPU, GPU, or other von Neumann architecture. Quantum annealers are special-purpose computers that use quantum effects to heuristically determine the set of Boolean variables that minimize a quadratic pseudo-Boolean function (an NP-hard problem). Natively programming such systems involves supplying them with a vector of function coefficients and receiving a vector of function-minimizing Booleans in return. The contribution of this work is to demonstrate how to compile conventional Code into a minimization problem for solution on a quantum annealer. The resulting Code can run either forward (from inputs to outputs) or backward (from outputs to inputs). We show how this capability can be exploited to simplify the expression and solution of problems in the NP complexity class.

Nicolas Delfosse - One of the best experts on this subject based on the ideXlab platform.

  • A construction of quantum LDPC Codes from Cayley graphs
    IEEE Transactions on Information Theory, 2013
    Co-Authors: Alain Couvreur, Nicolas Delfosse, Gilles Zemor
    Abstract:

    We study a construction of Quantum LDPC Codes proposed by MacKay, Mitchison and Shokrollahi in the draft [6]. It is based on the Cayley graph of F_2^n together with a set of generators regarded as the columns of the parity-check matrix of a Classical Code. We give a general lower bound on the minimum distance of the quantum Code in O(dn^2) where d is the minimum distance of the Classical Code. When the Classical Code is the [n; 1; n] repetition Code, we are able to compute the exact parameters of the associated quantum Code which are [[2^{n-1}, 2^{n/2}, 2^{n/2-1}]].

  • A Construction of Quantum LDPC Codes From Cayley Graphs
    IEEE Transactions on Information Theory, 2013
    Co-Authors: Alain Couvreur, Nicolas Delfosse, Gilles Zemor
    Abstract:

    We study a construction of quantum LDPC Codes proposed by MacKay, Mitchison, and Shokrollahi. It is based on the Cayley graph of \BBF2n together with a set of generators regarded as the columns of the parity-check matrix of a Classical Code. We give a general lower bound on the minimum distance of the quantum Code in O(dn2) where d is the minimum distance of the Classical Code. This bound is logarithmic in the blocklength 2n of the quantum Code. When the Classical Code is the [n,1,n] repetition Code, we are able to compute the exact parameters of the associated quantum Code which are [[2n, 2[(n+1)/2], 2[(n-1)/2]]].

  • A Construction of Quantum LDPC Codes from Cayley Graphs
    arXiv: Information Theory, 2012
    Co-Authors: Alain Couvreur, Nicolas Delfosse, Gilles Zemor
    Abstract:

    We study a construction of Quantum LDPC Codes proposed by MacKay, Mitchison and Shokrollahi. It is based on the Cayley graph of Fn together with a set of generators regarded as the columns of the parity-check matrix of a Classical Code. We give a general lower bound on the minimum distance of the Quantum Code in $\mathcal{O}(dn^2)$ where d is the minimum distance of the Classical Code. When the Classical Code is the $[n, 1, n]$ repetition Code, we are able to compute the exact parameters of the associated Quantum Code which are $[[2^n, 2^{\frac{n+1}{2}}, 2^{\frac{n-1}{2}}]]$.

  • ISIT - A construction of quantum LDPC Codes from Cayley graphs
    2011 IEEE International Symposium on Information Theory Proceedings, 2011
    Co-Authors: Alain Couvreur, Nicolas Delfosse, Gilles Zemor
    Abstract:

    We study a construction of Quantum LDPC Codes proposed by MacKay, Mitchison and Shokrollahi in the draft [6]. It is based on the Cayley graph of F 2 n together with a set of generators regarded as the columns of the parity-check matrix of a Classical Code. We give a general lower bound on the minimum distance of the quantum Code in O(dn2) where d is the minimum distance of the Classical Code. When the Classical Code is the [n, 1, n] repetition Code, we are able to compute the exact parameters of the associated quantum Code which are equation