Quantum Computing Circuits Based on Spin-Torque Qubit Architecture: Toward the Physical Realization of Quantum Computers

Quantum computers perform computations based on the principles of quantum mechanics, which enables faster speed and higher security than classical computers; they also have the ability to process a large amount of information via parallel processing. Some important concepts regarding quantum computers are qubits, quantum registers, quantum logic, quantum networks, quantum reversibility, quantum teleportation, quantum data compression, quantum cryptography, universal quantum computing, and quantum algorithms. Quantum computers rely on the basic quantum principles of superposition and entanglement. The time evolution of an arbitrary quantum state is computational ly more powerful than that of a digital logic state. Theoretical quantum computing based on the rotation of the qubits has proven that it is possible for quantum devices to address complex computing problems.