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Title: Quantum Computing

Abstract

No abstract provided.

Authors:
 [1]
  1. Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
Publication Date:
Research Org.:
Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
1415361
Report Number(s):
LA-UR-17-31406
DOE Contract Number:
AC52-06NA25396
Resource Type:
Technical Report
Country of Publication:
United States
Language:
English
Subject:
97 MATHEMATICS AND COMPUTING; Computer Science

Citation Formats

Pakin, Scott D. Quantum Computing. United States: N. p., 2017. Web. doi:10.2172/1415361.
Pakin, Scott D. Quantum Computing. United States. doi:10.2172/1415361.
Pakin, Scott D. Wed . "Quantum Computing". United States. doi:10.2172/1415361. https://www.osti.gov/servlets/purl/1415361.
@article{osti_1415361,
title = {Quantum Computing},
author = {Pakin, Scott D.},
abstractNote = {No abstract provided.},
doi = {10.2172/1415361},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Wed Dec 20 00:00:00 EST 2017},
month = {Wed Dec 20 00:00:00 EST 2017}
}

Technical Report:

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  • For several years now quantum computing has been viewed as a new paradigm for certain computing applications. Of particular importance to this burgeoning field is the development of an algorithm for factoring large numbers which obviously has deep implications for cryptography and national security. Implementation of these theoretical ideas faces extraordinary challenges in preparing and manipulating quantum states. The quantum transport group at Sandia has demonstrated world-leading, unique double quantum wires devices where we have unprecedented control over the coupling strength, number of 1 D channels, overlap and interaction strength in this nanoelectronic system. In this project, we study 1D-1Dmore » tunneling with the ultimate aim of preparing and detecting quantum states of the coupled wires. In a region of strong tunneling, electrons can coherently oscillate from one wire to the other. By controlling the velocity of the electrons, length of the coupling region and tunneling strength we will attempt to observe tunneling oscillations. This first step is critical for further development double quantum wires into the basic building block for a quantum computer, and indeed for other coupled nanoelectronic devices that will rely on coherent transport. If successful, this project will have important implications for nanoelectronics, quantum computing and information technology.« less
  • Over the last twenty years, there has been a boom in quantum science - i.e., the development and exploitation of quantum systems to enable qualitatively and quantitatively new capabilities, with high-impact applications and fundamental insights that can range across all areas of science and technology.
  • The application of concatenated codes to fault tolerant quantum computing is discussed. We have previously shown that for quantum memories and quantum communication, a state can be transmitted with error {epsilon} provided each gate has error at most c{epsilon}. We show how this can be used with Shor`s fault tolerant operations to reduce the accuracy requirements when maintaining states not currently participating in the computation. Viewing Shor`s fault tolerant operations as a method for reducing the error of operations, we give a concatenated implementation which promises to propagate the reduction hierarchically. This has the potential of reducing the accuracy requirementsmore » in long computations.« less
  • Our goal was to investigate the suitability of parallel supercomputer architectures for Quantum Monte Carlo (QMC). Because QMC allows one to study the properties of ions and electrons in a solid, it has important applications to condensed matter physics, chemistry, and materials science. research plan was to Our specific 1. Adapt quantum simulation codes which were highly optimized for vector supercomputers to run on the Intel Hypercube and Thinking Machines CM--5. 2. Identify architectural bottlenecks in communication, floating point computation, and node memory. Determine scalability with number of nodes. 3. Identify algorithmic changes required to take advantage of current andmore » prospective architectures. We have made significant progress towards these goals. We explored implementations of the p4 parallel programming system and the Message Passing Interface (MPI) libraries to run ``world-line`` and ``determinant`` QMC and Molecular Dynamics simulations on both workstation clusters (HP, Spare, AIX, Linux) and massively parallel supercomputers (Intel iPSC1860, Meiko CS-2, BM SP-X, Intel Paragon). We addressed issues of the efficiency of parallelization as a function of distribution of the problem over the nodes and the length scale of the interactions between particles. Both choices influence he frequency of inter-node communication and the size of messages passed. We found that using the message-passing paradigm on an appropriate machine (e.g., the ntel iPSC/860) an essentially linear speedup could be obtained.« less
  • Assumptions useful for fault tolerant quantum computing are stated and briefly discussed. We focus on assumptions related to properties of the computational system. The strongest form of the assumptions seems to be sufficient for achieving highly fault tolerant quantum computation. We discuss weakenings which are also likely to suffice.