Graphical and Programming Support for Simulations of Quantum Computations
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A New Family of Fault Tolerant Quantum Reed-Muller Codes
Clemson University TigerPrints All Theses Theses December 2020 A New Family of Fault Tolerant Quantum Reed-Muller Codes Harrison Beam Eggers Clemson University, [email protected] Follow this and additional works at: https://tigerprints.clemson.edu/all_theses Recommended Citation Eggers, Harrison Beam, "A New Family of Fault Tolerant Quantum Reed-Muller Codes" (2020). All Theses. 3463. https://tigerprints.clemson.edu/all_theses/3463 This Thesis is brought to you for free and open access by the Theses at TigerPrints. It has been accepted for inclusion in All Theses by an authorized administrator of TigerPrints. For more information, please contact [email protected]. A New Family of Fault Tolerant Quantum Reed-Muller Codes A Thesis Presented to the Graduate School of Clemson University In Partial Fulfillment of the Requirements for the Degree Master of Science Mathematics by Harrison Eggers December 2020 Accepted by: Dr. Felice Manganiello, Committee Chair Dr. Shuhong Gao Dr. Kevin James Abstract Fault tolerant quantum computation is a critical step in the development of practical quan- tum computers. Unfortunately, not every quantum error correcting code can be used for fault tolerant computation. Rengaswamy et. al. define CSS-T codes, which are CSS codes that admit the transversal application of the T gate, which is a key step in achieving fault tolerant computation. They then present a family of quantum Reed-Muller fault tolerant codes. Their family of codes admits a transversal T gate, but the asymptotic rate of the family is zero. We build on their work by reframing their CSS-T conditions using the concept of self-orthogonality. -
Fault-Tolerant Quantum Gates Ph/CS 219 2 February 2011
Fault-tolerant quantum gates Ph/CS 219 2 February 2011 Last time we considered the requirements for fault-tolerant quantum gates that act nontrivially on the codespace of a quantum error-correcting code. In the special case of a code that corrects t=1 error, the requirements are: -- if the gate gadget is ideal (has no faults) and its input is a codeword, then the gadget realizes the encoded operation U acting on the code space. -- if the gate gadget is ideal and its input has at most one error (is one-deviated from the codespace), then the output has at most one error in each output block. -- if the gate has one fault and its input has no errors, then the output has at most one error in each block (the errors are correctable). We considered the Clifford group, the finite subgroup of the m-qubit unitary group generated by the Hadamard gate H, the phase gate P (rotation by Pi/2 about the z-axis) and the CNOT gate. For a special class of codes, the generators of the Clifford group can be executed transversally (i.e., bitwise). The logical U can be done by applying a product of n U (or inverse of U) gates in parallel (where n is the code's length). If we suppose that the number of encoded qubits is k=1, then: -- the CNOT gate is transversal for any CSS code. -- the H gate is transversal for a CSS code that uses the same classical code to correct X errors and Z errors. -
Arxiv:2104.09539V1 [Quant-Ph] 19 Apr 2021
Practical quantum error correction with the XZZX code and Kerr-cat qubits Andrew S. Darmawan,1, 2 Benjamin J. Brown,3 Arne L. Grimsmo,3 David K. Tuckett,3 and Shruti Puri4, 5 1Yukawa Institute for Theoretical Physics (YITP), Kyoto University, Kitashirakawa Oiwakecho, Sakyo-ku, Kyoto 606-8502, Japan∗ 2JST, PRESTO, 4-1-8 Honcho, Kawaguchi, Saitama 332-0012, Japan 3Centre for Engineered Quantum Systems, School of Physics, University of Sydney, Sydney, New South Wales 2006, Australia 4 Department of Applied Physics, Yale University, New Haven, Connecticut 06511, USAy 5Yale Quantum Institute, Yale University, New Haven, Connecticut 06511, USA (Dated: April 21, 2021) The development of robust architectures capable of large-scale fault-tolerant quantum computa- tion should consider both their quantum error-correcting codes, and the underlying physical qubits upon which they are built, in tandem. Following this design principle we demonstrate remarkable error correction performance by concatenating the XZZX surface code with Kerr-cat qubits. We contrast several variants of fault-tolerant systems undergoing different circuit noise models that reflect the physics of Kerr-cat qubits. Our simulations show that our system is scalable below a threshold gate infidelity of pCX 6:5% within a physically reasonable parameter regime, where ∼ pCX is the infidelity of the noisiest gate of our system; the controlled-not gate. This threshold can be reached in a superconducting circuit architecture with a Kerr-nonlinearity of 10MHz, a 6:25 photon cat qubit, single-photon lifetime of > 64µs, and thermal photon population < 8%.∼ Such parameters are routinely achieved in superconducting∼ circuits. ∼ I. INTRODUCTION qubit [22, 34, 35]. -
Quantum Error-Correcting Codes by Concatenation QEC11
Quantum Error-Correcting Codes by Concatenation QEC11 Second International Conference on Quantum Error Correction University of Southern California, Los Angeles, USA December 5–9, 2011 Quantum Error-Correcting Codes by Concatenation Markus Grassl joint work with Bei Zeng Centre for Quantum Technologies National University of Singapore Singapore Markus Grassl – 1– 07.12.2011 Quantum Error-Correcting Codes by Concatenation QEC11 Why Bei isn’t here Jonathan, November 24, 2011 Markus Grassl – 2– 07.12.2011 Quantum Error-Correcting Codes by Concatenation QEC11 Overview Shor’s nine-qubit code revisited • The code [[25, 1, 9]] • Concatenated graph codes • Generalized concatenated quantum codes • Codes for the Amplitude Damping (AD) channel • Conclusions • Markus Grassl – 3– 07.12.2011 Quantum Error-Correcting Codes by Concatenation QEC11 Shor’s Nine-Qubit Code Revisited Bit-flip code: 0 000 , 1 111 . | → | | → | Phase-flip code: 0 + ++ , 1 . | → | | → | − −− Effect of single-qubit errors on the bit-flip code: X-errors change the basis states, but can be corrected • Z-errors at any of the three positions: • Z 000 = 000 | | “encoded” Z-operator Z 111 = 111 | −| = Bit-flip code & error correction convert the channel into a phase-error ⇒ channel = Concatenation of bit-flip code and phase-flip code yields [[9, 1, 3]] ⇒ Markus Grassl – 4– 07.12.2011 Quantum Error-Correcting Codes by Concatenation QEC11 The Code [[25, 1, 9]] The best single-error correcting code is = [[5, 1, 3]] • C0 Re-encoding each of the 5 qubits with yields = [[52, 1, 32]] -
Rényi Divergences, Bures Geometry and Quantum Statistical Thermodynamics
entropy Article Rényi Divergences, Bures Geometry and Quantum Statistical Thermodynamics Ali Ümit Cemal Hardal * and Özgür Esat Müstecaplıo˘glu Department of Physics, Koç University, Istanbul˙ 34450, Turkey; [email protected] * Correspondence: [email protected]; Tel.: +90-212-338-1471 Academic Editor: Ignazio Licata Received: 22 November 2016; Accepted: 16 December 2016; Published: 19 December 2016 Abstract: The Bures geometry of quantum statistical thermodynamics at thermal equilibrium is investigated by introducing the connections between the Bures angle and the Rényi 1/2-divergence. Fundamental relations concerning free energy, moments of work, and distance are established. Keywords: thermodynamics; quantum entropies; geometry 1. Introduction Galileo once said “philosophy is written in the language of mathematics and the characters are triangles, circles and other figures” [1]. Since then, natural philosophy and geometry evolved side by side, leading groundbreaking perceptions of the foundations of today’s modern science. A particular example was introduced by Gibbs [2,3], who successfully described the theory of thermodynamics by using convex geometry in which the coordinates of this special phase space are nothing but the elements of classical thermodynamics. While the Gibbsian interpretation has been successful for the understanding of the relations among the thermodynamical entities, it lacks the basic notion of a geometry: the distance. The latter constitutes the fundamental motivation for Weinhold’s geometry [4], where an axiomatic algorithm leads a scalar product, and thus induces a Riemannian metric into the convex Gibbsian state space. Later, Ruppeiner proposed that any instrument of a geometry that describes a thermodynamical state of a system should lead to physically meaningful results [5]. -
Basic Probability Theory A
Basic Probability Theory A In order to follow many of the arguments in these notes, especially when talking about entropies, it is necessary to have some basic knowledge of probability theory. Therefore, we review here the most important tools of probability theory that are used. One of the basic notions of probability theory that also frequently appears throughout these notes is that of a discrete random variable. A random variable X can take one of several values, the so-called realizations x,givenbythealphabet X. The probability that a certain realization x ∈ X occurs is given by the probability distribution pX(x). We usually use upper case letters to denote the random variable, lower case letters to denote realizations thereof, and calligraphic letters to denote the alphabet. Suppose we have two random variables X and Y , which may depend on each other. We can then define the joint probability distribution pX,Y (x, y) of X and Y that tells you the probability that Y = y and X = x. This notion (and the following definition) can be expanded to n random variables, but we restrict ourselves to the case of pairs X, Y here to keep the notation simple. Given the joint probability distribution of the pair X, Y , we can derive the marginal distribution PX(x) by pX(x) = pX,Y (x, y) ∀ x ∈ X (A.1) y∈Y and analogously for PY (y). The two random variables X and Y are said to be independent if pX,Y (x, y) = pX(x)pY (y). (A.2) © The Author(s), under exclusive license to Springer Nature Switzerland AG 2021 219 R. -
QUANTUM COMPUTER and QUANTUM ALGORITHM for TRAVELLING SALESMAN PROBLEM Utpal Roy, Sanchita Pal Chawdhury, Susmita Nayek
ISSN: 0974-3308, VOL. 2, NO. 1, JUNE 2009 © SRIMCA 54 QUANTUM COMPUTER AND QUANTUM ALGORITHM FOR TRAVELLING SALESMAN PROBLEM Utpal Roy, Sanchita Pal Chawdhury, Susmita Nayek ABSTRACT Depending upon the extraordinary power of Quantum Computing Algorithms various branches like Quantum Cryptography, Quantum Information Technology, Quantum Teleportation have emerged [1-4]. It is thought that this power of Quantum Computing Algorithms can also be successfully applied to many combinatorial optimization problems. In this article, a class of combinatorial optimization problem is chosen as case study under Quantum Computing. These problems are widely believed to be unsolvable in polynomial time. Mostly it provides suboptimal solutions in finite time using best known classical algorithms. Travelling Salesman Problem (TSP) is one such problem to be studied here. A great deal of effort has already been devoted towards devising efficient algorithms that can solve the problem [5-18]. Moreover, the methods of finding solutions for the TSP with Artificial Neural Network and Genetic Algorithms [5-8] do not provide the exact solution to the problems for all the cases, excepting a few. A successful attempt has been made to have a deterministic solution for TSP by applying the power of Quantum Computing Algorithm. Keywords: Quantum Computing, Travelling Salesman Problem, Quantum algorithms. 1. INTRODUCTION A quantum computer is a device that can arbitrarily manipulate the quantum state of a part or itself. The field of quantum computation is largely a body of theoretical promises for some impressively fast algorithms which could be executed on quantum computers. The field of quantum computing has advanced remarkably in the past few years since Shor [1] presented his quantum mechanical algorithm for efficient prime factorization of very large numbers, potentially providing an exponential speedup over the fastness on known classical algorithm. -
Download the 3Rd Edition of the Book of Abstracts
Book of Abstracts 3rd BSC International Doctoral Symposium Editors Nia Alexandrov María José García Miraz Graphic and Cover Design: Cristian Opi Muro Laura Bermúdez Guerrero This is an open access book registered at UPC Commons (http://upcommons.upc.edu) under a Creative Commons license to protect its contents and increase its visibility. This book is available at http://www.bsc.es/doctoral-symposium-2016 published by: Barcelona Supercomputing Center supported by: The “Severo Ochoa Centres of Excellence" programme 3rd Edition, September 2016 Introduction ACKNOWLEDGEMENTS The BSC Education & Training team gratefully acknowledges all the PhD candidates, Postdoc researchers, experts and especially the Keynote Speaker Francisco J. Doblas-Reyes and the tutorial lecturers Vassil Alexandrov and Javier Espinosa, for contributing to this Book of Abstracts and participating in the 3rd BSC International Doctoral Symposium 2016. We also wish to expressly thank the volunteers that supported the organisation of the event: Carles Riera and Felipe Nathan De Oliveira. BSC Education & Training team [email protected] 5 Introduction 6 Introduction CONTENTS EDITORIAL COMMENT ................................................................................................ 11 WELCOME ADDRESS .................................................................................................. 13 PROGRAM .................................................................................................................... 15 KEYNOTE SPEAKER ................................................................................................... -
Universal Quantum Computation with Ideal Clifford Gates and Noisy Ancillas
PHYSICAL REVIEW A 71, 022316 ͑2005͒ Universal quantum computation with ideal Clifford gates and noisy ancillas Sergey Bravyi* and Alexei Kitaev† Institute for Quantum Information, California Institute of Technology, Pasadena, 91125 California, USA ͑Received 6 May 2004; published 22 February 2005͒ We consider a model of quantum computation in which the set of elementary operations is limited to Clifford unitaries, the creation of the state ͉0͘, and qubit measurement in the computational basis. In addition, we allow the creation of a one-qubit ancilla in a mixed state , which should be regarded as a parameter of the model. Our goal is to determine for which universal quantum computation ͑UQC͒ can be efficiently simu- lated. To answer this question, we construct purification protocols that consume several copies of and produce a single output qubit with higher polarization. The protocols allow one to increase the polarization only along certain “magic” directions. If the polarization of along a magic direction exceeds a threshold value ͑about 65%͒, the purification asymptotically yields a pure state, which we call a magic state. We show that the Clifford group operations combined with magic states preparation are sufficient for UQC. The connection of our results with the Gottesman-Knill theorem is discussed. DOI: 10.1103/PhysRevA.71.022316 PACS number͑s͒: 03.67.Lx, 03.67.Pp I. INTRODUCTION AND SUMMARY additional operations ͑e.g., measurements by Aharonov- Bohm interference ͓13͔ or some gates that are not related to The theory of fault-tolerant quantum computation defines topology at all͒. Of course, these nontopological operations an important number called the error threshold. -
Models of Quantum Computation and Quantum Programming Languages
Models of quantum computation and quantum programming languages Jaros law Adam MISZCZAK Institute of Theoretical and Applied Informatics, Polish Academy of Sciences, Ba ltycka 5, 44-100 Gliwice, Poland The goal of the presented paper is to provide an introduction to the basic computational mod- els used in quantum information theory. We review various models of quantum Turing machine, quantum circuits and quantum random access machine (QRAM) along with their classical counter- parts. We also provide an introduction to quantum programming languages, which are developed using the QRAM model. We review the syntax of several existing quantum programming languages and discuss their features and limitations. I. INTRODUCTION of existing models of quantum computation is biased towards the models interesting for the development of Computational process must be studied using the fixed quantum programming languages. Thus we neglect some model of computational device. This paper introduces models which are not directly related to this area (e.g. the basic models of computation used in quantum in- quantum automata or topological quantum computa- formation theory. We show how these models are defined tion). by extending classical models. We start by introducing some basic facts about clas- A. Quantum information theory sical and quantum Turing machines. These models help to understand how useful quantum computing can be. It can be also used to discuss the difference between Quantum information theory is a new, fascinating field quantum and classical computation. For the sake of com- of research which aims to use quantum mechanical de- pleteness we also give a brief introduction to the main res- scription of the system to perform computational tasks. -
Introduction to Quantum Error Correction
Introduction to Quantum Error Correction Gilles Zémor Nomade Lodge, May 2016 1 Qubits, quantum computing 1.1 Qubits A qubit is a mathematical description of a particle, e.g. a photon, it is a vector of unit norm in a Hilbert space H of dimension 2. It is customary to give oneself a basis of this space, that is written in Dirac notation (j0i; j1i) rather than the usual mathematical notation (e0; e1). A qubit is therefore a quantity expressed as αj0i + βj1i with jαj2 + jβj2 = 1. The physical state of n particles is described by a vector in the Hilbert space H⊗n, which consists of all complex linear combinations of products jx1i⊗jx2i⊗· · ·⊗jxni, where jxii ranges over the two basis vectors of the i-th copy of the Hilbert space H. Typically one uses the convention xi 2 f0; 1g and the basis vectors of the 2n-dimensional complex vector space H⊗n are written, to lighten notation as jx1ijx2i · · · jxni or simply as jx1x2 : : : xni: This basis of H⊗n will be referred to as the computational basis. Quantum states are described by vectors of unit norm in H⊗n. Quantum states are also not changed by multiplication by a complex number of modulus 1, so that strictly speaking quantum states are unit vectors of H⊗n modulo the multiplicative group of complex numbers of unit norm. Unitary transformations. A quantum state j i may be changed into another quantum state j 0i by any unitary transformation U of the Hilbert space H⊗n. A unitary transformation is an operator of H⊗n that preserves the hermitian inner product. -
One-Way Quantum Computer Simulation
One-Way Quantum Computer Simulation Eesa Nikahd, Mahboobeh Houshmand, Morteza Saheb Zamani, Mehdi Sedighi Quantum Design Automation Lab Department of Computer Engineering and Information Technology Amirkabir University of Technology Tehran, Iran {e.nikahd, houshmand, szamani, msedighi}@aut.ac.ir Abstract— In one-way quantum computation (1WQC) model, universal quantum computations are performed using measurements to designated qubits in a highly entangled state. The choices of bases for these measurements as well as the structure of the entanglements specify a quantum algorithm. As scalable and reliable quantum computers have not been implemented yet, quantum computation simulators are the only widely available tools to design and test quantum algorithms. However, simulating the quantum computations on a standard classical computer in most cases requires exponential memory and time. In this paper, a general direct simulator for 1WQC, called OWQS, is presented. Some techniques such as qubit elimination, pattern reordering and implicit simulation of actions are used to considerably reduce the time and memory needed for the simulations. Moreover, our simulator is adjusted to simulate the measurement patterns with a generalized flow without calculating the measurement probabilities which is called extended one-way quantum computation simulator (EOWQS). Experimental results validate the feasibility of the proposed simulators and that OWQS and EOWQS are faster as compared with the well-known quantum circuit simulators, i.e., QuIDDPro and libquantum for simulating 1WQC model1. Keywords-Quantum Computing, 1WQC, Simulation 1 INTRODUCTION Quantum information [2] is an interdisciplinary field which combines quantum physics, mathematics and computer science. Quantum computers have some advantages over the classical ones, e.g., they give dramatic speedups for tasks such as integer factorization [3] and database search [4].