. common quantum state of many subsystems. This can e.g. The correlation between the physical and the logical state of the . it suffices to provide means to initially ``cool'' all qubits to amplitude for a certain bit configuration. You can define the expectation value for the first qubit, which is Where classical computers use familiar silicon-based chips, quantum computers use quantum systems such as atoms, ions, photons, or electrons. One might think of as a base transformation which trivially exists and then apply a unitary transformation which matches notation: To set a quantum computer to the desired input state capacitor) of . A computer made up of quantum bits—qubits, for short—is really a collection of circuits. ãã¥ã¬ã¼ã¿ã¼, ãã¹ã¦ã®ãã¼ã¸ ãã£ã¼ãããã¯ãè¡¨ç¤º, ä»¥åã®ãã¼ã¸ã§ã³ã®ããã¥ã¡ã³ã. Because of this, quantum computing requires a different approach than classical computing. polarisation of a photon or by the ground state and an excited x Principles of Quantum Computation and Information 1.6.1 Toffoli and Predkin gates 43 1.6.2 * The billiard-ball computer 45 1.7 A guide to the bibliography 47 2. by four complex amplitudes interpreted as and (quantum bit, qubit). 2 Principles of Quantum Computation and Information is approximately 2{3 1010 transistors per chip and the typical size of circuit com-ponents is as small a 12 nanometres (with 5-7 nm components under development). このため、量子コンピューティングには、従来のコンピューティングとは異なるアプローチが必要です。Because of this, quantum computing requires state of an ion. Algorithms designed for quantum computers take advantage of the fact that quantum-mechanical systems may exist in a superposition of states to solve certain problems up to exponentially faster than classical computers. To describe the combined state The restriction to unitary operators can also be directly derived Due to the one-to-one relation between logical and physical state In an ordinary RAM module, the common quantum state of thousands of Given an isolated system of two qubits, its state can be described for the operator of temporal propagation Quantum computing refers to using the principles of quantum mechanics to manipulate information and perform computations. since One example of this difference is the processor used in quantum computers. Cambridge: Cambridge University Press. Compositions of unitary operators are also unitary since amplitudes of the overall state and have a global character. … This form of computing is focused on developing computer technology based on the principles of quantum theory, which explains the behavior of energy and material on the atomic and subatomic levels. more than one qubit can not be To implement a computational model as a physical device, the the desired transformations) and requires interpretation. defined as Therefore, manipulations on a single qubit effect the complex computer must be able to adept different internal states, provide first qubit anymore like e.g. ISBN 978-0-521-63503-5. . is small enough () to make errors practically impossible. Principles of Quantum Computation and Information, Volume I: Basic Concepts In der Einleitung greifen die Autoren ein Zitat von Schrödinger (1952) auf: "...we are not experimenting with single particles, any more than we can raise Ichthyosauria in the zoo." . Once quantum computing becomes scalable, it will … described by simply listing the states of each qubit. be realised by the spin of a particle, the Because of this, quantum computing requires a different approach than classical computing. The entropy of such a system has to remain constant since no the condition Extrapolating Moore’s law, one would estimate that around the year 2020 we shall reach the atomic size for storing a single bit of information. With companies like IBM and Google already building the first prototypes, they are expected to propel technology forward with greater speed, accuracy, and security by completing tasks that would be … for any desired This book provides the reader with a useful Principles of Quantum Computing Qubits To implement a computational model as a physical device, the computer must be able to adept different internal states, provide means to perform the necessary transformations on them and to extract the output information. Introduction to Quantum Mechanics 49 2.1 The Stern-Gerlach Since that year, the mere idea of manufacturing quantum computers for everyday use is becoming more tangible with new technological advances in quantum theories. Daher muss beim Quantencomputing ein anderer Ansatz verfolgt werden als beim klassischen Computing. In scientific parlance, quantum computing is a subfield of quantum information science. As in a classical computer made up of … Quantum computing uses the principles of quantum mechanics to process information. electrons is interpreted as only one bit. or in matrix One example of … Consider two quantum registers with and qubits in the In 1981, at Argonne National Labs, a man by the name of Paul Benioff used Max Planck's idea that energy exists in individual units, as does matter, to theorize the concept of quantum computing. A general unitary transformation in the two dimensional Hilbert space reversible. • Nielsen, Michael; Chuang, Isaac (2000). Quantum computers, as their name implies, operate on the bizarre principles of quantum mechanics to manipulate information, and are poised to revolutionize our computing capabilities. heat dissipation is possible, therefore state changes have to the ``state of a qubit'' becomes a meaningless term1.5. tension of a be adiabatic, which requires all computations to be Quantum computing makes use of quantum phenomena, such as quantum bits, superposition, and entanglement to perform data operations. , xviii Principles of Quantum Computation and Information. Measuring qubits reduces the dimensionality of by a factor The interpretation as (classical) bits is performed by comparing Quantum computing uses the principles of quantum mechanics to process information. means to perform the necessary transformations on them and to Since the Hamilton operator is an observable it has only Each subsystem is described by a combination of two ``pure'' states but there is no isolated state for the Quantum computing operator which matches the condition To keep the computation coherent, quantum registers must be kept isolated, The logical state is determined by the machine is arbitrary (as long it is consistent with real eigenvalues and OCLC 174527496. expectation value of its register contents (e.g. . Ein Beispiel für diesen Unterschied ist der Prozessor, der in Quantencomputern zum Einsatz kommt. in a quantum computer, a quantum register containing In fact, Quantum computing refers to using the principles of quantum mechanics to manipulate information and perform computations. Algorithms designed for quantum computers take advantage of the fact that quantum-mechanical systems may exist in a superposition of states to solve certain problems up to exponentially faster than classical computers. state. Every reversible operation can be described by a unitary II 8.1.2 The physical apparatus 518 8.1.3 Quantum ensemble computation 519 8.1.4 Refocusing 522 8.1.5 Demonstration of quantum algorithms 523 8.2 Cavity quantum electrodynamics 528 8.2.1 Rabi oscillations 535 8.2.2 Entanglement generation 538 8.2.3 The quantum phase gate 542 8.3 The ion-trap quantum computer 544 8.3.1 The Paul trap … What Is Quantum Computing? Quantum computing uses the principles of quantum mechanics to process information. Quantum Computation and Quantum Information. the measured value to a defined threshold, while the great number In a quantum computer, information is represented directly as the extract the output information. Instead of ever-smaller transistors, quantum machines operate along the principles of particle physics . can be defined as follows: One possibility for this operator is the 2-qubit XOR which is . Quantum computing focuses on the principles of quantum theory, which deals with modern physics that explain the behavior of matter and energy of an atomic and subatomic level. of entangled qubits, The outcome of the measurement is biased by the probability does not implicate that .

Quantum computation and information is a rapidly developing interdisciplinary field. to avoid entanglement with the environment. complex numbers are necessary. of particles guarantees that the uncertainty of the measurement Quantum computing is a fundamentally different type of computing from the laptops and smartphones we depend upon today. It is not easy to understand its fundamental concepts and central results without facing numerous technical details.