In other words, quantum computers obey the Church–Turing thesis. Conversely, any problem that can be solved by a quantum computer can also be solved by a classical computer, at least in principle given enough time. Īny computational problem that can be solved by a classical computer can also be solved by a quantum computer. Quantum computers therefore require error correction. It is particularly difficult to maintain qubits' quantum states, as they suffer from quantum decoherence. There are currently a number of significant obstacles to constructing useful quantum computers. : 2–13 These qubits may be designed differently, depending on the full quantum computer's computing model, as to whether quantum logic gates, quantum annealing, or adiabatic quantum computation are employed. When it is measured, however, it is always 0 or 1 the probability of either outcome depends on the qubit's quantum state immediately prior to measurement.Įfforts towards building a physical quantum computer focus on technologies such as transmons, ion traps and topological quantum computers, which aim to create high-quality qubits. A qubit can be in a 1 or 0 quantum state, or in a superposition of the 1 and 0 states. Most models are based on the quantum bit, or ' qubit', which is somewhat analogous to the bit in classical computation. Other models include the quantum Turing machine, quantum annealing, and adiabatic quantum computation. There are several models of quantum computation with the most widely used being quantum circuits. The study of quantum computing is a subfield of quantum information science. Though current quantum computers are too small to outperform usual (classical) computers for practical applications, larger realizations are believed to be capable of solving certain computational problems, such as integer factorization (which underlies RSA encryption), substantially faster than classical computers. Devices that perform quantum computations are known as quantum computers. Quantum computing is a type of computation whose operations can harness the phenomena of quantum mechanics, such as superposition, interference, and entanglement.

IBM Q System One (2019), the first circuit-based commercial quantum computer

Quantum break crack status