What is Quantum Computing? | Definition
Quantum computing comprises aspects of computer science, mathematics and physics in which the principles of quantum theory are utilized for the development of technologies, storing of data and the deciphering of complex problems. The concepts of quantum physics are used to solve problems that are too complex for a classical computer to solve.
Quantum computing provides an advancement in computing capabilities due to its high performance in certain use cases. The application of quantum computers offers a faster work rate in areas such as the simulation of physical systems, portfolio optimization, machine learning (ML) and integer factorization. It also has the potential for use in different industrial sectors like healthcare, pharmaceuticals, cybersecurity, manufacturing and finance.
How does a Quantum Computer function?
Both quantum computers and classical computers have circuits, chips, and logic gates and are operated by algorithms like sequential instructions. A quantum computer’s basic unit of memory is a quantum bit or qubit. As classical computers encode information in binary or bits which are in 0s and 1s, quantum computing uses 0s, 1s and both 0 and 1 simultaneously.
These qubits process information quite differently such as being in a superposition or entanglement in the sense that the ones and zeros can be in a simultaneous state or multiple states at the same time where they are entangled in such a way that they are connected quantum mechanically to each other. These characteristics offer quantum computers more capabilities in processing power than classical computers.
The qubits of quantum computing are represented by quantum particles and are made through the manipulation of electrons, photons, atoms or ions (electrically charged molecules or atoms), or by the nanoengineering of artificial atoms with the use of a printing method known as lithography.
Quantum computers require a crucial amount of energy and cooling to function accurately due to their intensive resource demand. These requirements contribute to the structure of the hardware of quantum computing which is mostly comprised of cooling systems that maintain the superconducting processor at a certain super-cooled temperature. The power and capabilities of quantum computers multiply exponentially with more qubits.
The Principles of Quantum Computing
A qubit being in a superposition state means it can represent a sum of two or more other distinct states at the same time. This feature makes it possible and easier for quantum computers to perform specific calculations much faster and more effectively than classical computers and to process multiple operations simultaneously.
The Quantum information it contains is placed by the qubits in a state of superposition which is a combination of all possible configurations of the qubit. Qubits configured in a superposition can create complex and multidimensional computational spaces which help in representing complex problems in new ways.
This feature entails the situation in which two qubits can be coordinated in a way that the state of one qubit affects the state of the other, even after being physically separated. This enhances the creation of quantum circuits that are more powerful than classical circuits.
When pairs of qubits are made to be entangled, the two qubits exist in a single state and the changes made to one qubit affect the other in a predictable way. The spin state of one entangled particle, up or down, impacts the spin of the other in the opposite direction. Qubits separated by great distances can interact with each other instantaneously with the help of quantum entanglement.
This relationship is usually taken advantage of by quantum algorithms for solving complex problems. The addition of qubits is done exponentially which leads to a huge increase in the power and ability of quantum computing while increasing the number of bits in classical computers increases their power only linearly.
This is exhibited when the quantum state of qubits deteriorates. The disturbance of the quantum state by temperature changes, radiation or vibrations causes qubits to fall out of superposition and leads to a collapse of computations or the presence of errors in quantum computing.
Therefore, qubits should be protected from such disturbances or interferences with the help of hardware installations like vacuum chambers, supercooled refrigerators and insulation.