In quantum computing, quantum state produces the basic unit of memory called 'qubit'

Quantum computers are machines that use the properties of quantum physics to store data and perform calculations based on the probability of an object's state before it is measured. This can be extremely advantageous for certain tasks where they could vastly outperform even the best supercomputers.

Quantum computers can process massive and complex datasets more efficiently than classical computers. They use the fundamentals of quantum mechanics to speed up the process of solving complex calculations. Often, these computations incorporate a seemingly unlimited number of variables and the potential applications span industries from genomics to finance.

Classic computers, which include smartphones and laptops, carry out logical operations using the definite position of a physical state. They encode information in binary 'bits' that can either be 0s or 1s. In quantum computing, operations instead use the quantum state of an object to produce the basic unit of memory called as a quantum bit or qubit. Qubits are made using physical systems, such as the spin of an electron or the orientation of a photon. These systems can be in many different arrangements all at once, a property known as quantum superposition. Qubits can also be inextricably linked together using a phenomenon called quantum entanglement. The result is that a series of qubits can represent different things simultaneously. These states are the undefined properties of an object before they've been detected, such as the spin of an electron or the polarization of a photon.

Instead of having a clear position, unmeasured quantum states occur in a mixed 'superposition' that can be entangled with those of other objects as their final outcomes will be mathematically related even. The complex mathematics behind these unsettled states of entangled 'spinning coins' can be plugged into special algorithms to make short work of problems that would take a classical computer a long time to work out.

History of Quantum Computers

American physicist and Nobel laureate Richard Feynman gave a note about quantum computers as early as 1959. He stated that when electronic components begin to reach microscopic scales, effects predicted by quantum mechanics occur, which might be exploited in the design of more powerful computers.

During the 1980s and 1990s, the theory of quantum computers advanced considerably beyond Feynman's early speculation. In 1985, David Deutsch of the University of Oxford described the construction of quantum logic gates for a universal quantum computer. Peter Shor of AT&T devised an algorithm to factor numbers with a quantum computer that would require as few as six qubits in 1994. Later in 1998, Isaac Chuang of Los Alamos National Laboratory, Neil Gershenfeld of Massachusetts Institute of Technology (MIT) and Mark Kubince of the University of California created the first quantum computer with 2 qubits, that could be loaded with data and output a solution.

Recently, Physicist David Wineland and his colleagues at the US National Institute for Standards and Technology (NIST) announced that they have created a 4-qubit quantum computer by entangling four ionized beryllium atoms using an electromagnetic trap. Today, quantum computing is poised to upend entire industries starting from telecommunications to cybersecurity, advanced manufacturing, finance medicine and beyond.

Types of Quantum Computers

There are three primary types of quantum computing. Each type differs by the amount of processing power (qubits) needed and the number of possible applications, as well as the time required to become commercially viable.

Quantum Annealing

Quantum annealing is best for solving optimization problems. Researchers are trying to find the best and most efficient possible configuration among many possible combinations of variables.

Volkswagen recently conducted a quantum experiment to optimize traffic flows in the overcrowded city of Beijing, China. The experiment was run in partnership with Google and D-Wave Systems. Canadian company D-Wave developed quantum annealer. But, it is difficult to tell whether it actually has any real 'quantumness' so far. The algorithm could successfully reduce traffic by choosing the ideal path for each vehicle.

Quantum Simulations

Quantum simulations explore specific problems in quantum physics that are beyond the capacity of classical systems. Simulating complex quantum phenomena could be one of the most important applications of quantum computing. One area that is particularly promising for simulation is modeling the effect of a chemical stimulation on a large number of subatomic particles also known as quantum chemistry.

Universal Quantum Computing

Universal quantum computers are the most powerful and most generally applicable, but also the hardest to build. Remarkably, a universal quantum computer would likely make use of over 100,000 qubits and some estimates put it at 1M qubits. But to the disappointment, the most qubits we can access now is just 128. The basic idea behind the universal quantum computer is that you could direct the machine at any massively complex computation and get a quick solution. This includes solving the aforementioned annealing equations, simulating quantum phenomena, and more.