Abstract Classical combinational logic circuits (CCLCs) are widely used in various fields. Corresponding to the CCLCs, here schemes are given for some quantum combinational logic circuits (QCLCs) based on the quantum NAND tree. Three typical circuits, adder, comparator, and seven‐segment display decoder, are discussed in detail as examples. All the designs of the schemes are based on the quantum random walk theory. Furthermore, these QCLCs are mapped onto the classical circuit networks and design new types of CCLCs, and take advantage of the fact that there is a good correspondence between the voltage in the circuit satisfying Kirchhoff's law and the system wave function satisfying the Schrodinger equation. These CCLCs that are designed have exponential speedup functions compared with conventional ones, which have been demonstrated experimentally. Because classical circuit networks possess good scalability and stability, the realization of QCLCs on classical circuits is expected to have potential applications for information processing in the era of big data.
Abstract Classical combinational logic circuits (CCLCs) are widely used in various fields. Corresponding to the CCLCs, here schemes are given for some quantum combinational logic circuits (QCLCs) based on the quantum NAND tree. Three typical circuits, adder, comparator, and seven‐segment display decoder, are discussed in detail as examples. All the designs of the schemes are based on the quantum random walk theory. Furthermore, these QCLCs are mapped onto the classical circuit networks and design new types of CCLCs, and take advantage of the fact that there is a good correspondence between the voltage in the circuit satisfying Kirchhoff's law and the system wave function satisfying the Schrodinger equation. These CCLCs that are designed have exponential speedup functions compared with conventional ones, which have been demonstrated experimentally. Because classical circuit networks possess good scalability and stability, the realization of QCLCs on classical circuits is expected to have potential applications for information processing in the era of big data.
Compared with classical algorithms, quantum algorithms can show the advantage of exponential speedup in solving some problems. Solving the NAND‐Tree problem is a typical example, which can be speed up exponentially by quantum walk. This scheme is groundbreaking due to the universality of the negative‐AND (NAND) gate. In fact, the NAND gate is also universal for classical computation, making it an important target for development. Herein, the quantum NAND‐Tree onto the classical circuit network is mapped and a new type of classical logic circuit with the NAND gate that can perform the quantum algorithms is designed. These classical logic gates that are designed have exponential speedup functions compared with conventional ones. Because classical circuit networks possess good scalability and stability, the present scheme is expected to have potential applications for information processing in the era of big data.
Quantum computing, which is the most famed topic in this era, a combination of quantum mechanics from the 1900s and the computing point of view, takes a huge place in the quantum realm. Starting from the foundation of abacus since 2700–2300 BC, we humans have always been trying to compute in different ways, and the most modern way of doing it comes with the binary system. Bit is the smallest unit of a binary system and can be in two states, either 0 or 1. On the contrary, quantum computing deals with the “quantum bit” or “qubit”; possible outcomes from the qubits are neither 0 nor 1. It will always be a combination of 0 and 1, which is based on the superposition principle from quantum physics. In this chapter, details of quantum logic gates are discussed for the circuit design perspective, which will be achievable for future realization of quantum computers. Architecture and corresponding formation of basic quantum circuits are discussed, along with the methods of quantum computing. How the technique differs from conventional approaches is also highlighted. The work may be directed toward future hardware realization of quantum information processing.
Quantum walks, being the quantum analog of classical random walks, are expected to provide a fruitful source of quantum algorithms. A few such algorithms have already been developed, including the ``glued trees'' algorithm, which provides an exponential speedup over classical methods, relative to a particular quantum oracle. Here, we discuss the possibility of a quantum walk algorithm yielding such an exponential speedup over possible classical algorithms, without the use of an oracle. We provide examples of some highly symmetric graphs on which efficient quantum circuits implementing quantum walks can be constructed and discuss potential applications to quantum search for marked vertices along these graphs.
Recent advancements in computing speed and capacity of Artificial Intelligence (AI) algorithms have reached a saturation level in performance due to the continuous application of Moore's law which resulted in the memory wall phenomenon. Quantum computing (QC), based on the principles of quantum mechanics which include superposition and entanglement, has the potential to contribute to the advancements of AI by providing exponential speedup. Quantum computers use quantum bits, also known as qubits, as the metric to demonstrate the power of quantum technology. Qubits, the fundamental unit of quantum information can exist in two states, 0 and 1, simultaneously, leveraging the principle of superposition. Quantum gates are the building blocks of quantum circuits, operating on qubits to transform one quantum state into another, and are comparative to classical logic gates. Designing and simulating quantum circuits can be completed using the Qiskit library design by IBM. Qiskit is a cloud-based, open access platform to real quantum computers with 5 to 16 qubits. This paper offers a straightforward tutorial on implementing one, two and three-qubit quantum gates, as well as designing quantum circuits using the Qiskit library, illustrated with an example of a quantum half adder implementation.
ABSTRACT Universal quantum computation that consists of producing arbitrary input states and executing universal unitary gates is an important goal for the future information field. However, realizing a device that performs practical universal quantum computation is tricky. This is because it requires a scalable qubit system with long coherence time and good controls, which is harsh for most current platforms. Here, we provide a novel scheme to emulate the universal quantum computer by designing a classical circuit network. In the circuit network, we encode information using correlated electrical signals. The information processing elements that correspond to the universal quantum gate set are designed and embedded into the circuit network, which gives the classical circuit networks processing functions similar to that of universal quantum computation. Taking the analogy of two‐qubit processor as an example, we experimentally verify that our proposal works well. Because classical circuit networks possess good scalability and stability, the present scheme is expected to avoid some problems faced by the quantum schemes. Thus, our findings are advantageous for information processing in the era of big data.
Abstract Based on the correspondence between circuit Laplacian and Schrodinger equations, recent investigations have shown that classical electric circuits can be used to simulate various topological physics and Schrödinger's equation. Furthermore, a series of quantum‐inspired information processing has been implemented by using classical electric circuit networks. In this review, the similarity between the circuit Laplacian and the lattice Hamiltonian is analyzed, with topological physics introduced based on classical circuits. Subsequently, reviews of the research progress in quantum‐inspired information processing based on the electric circuit are provided, including discussions of topological quantum computing with classical circuits, quantum walk based on classical circuits, quantum combinational logics based on classical circuits, electric‐circuit realization of fast quantum search, implementing unitary transforms and so on.