By utilising some of the nearly magical properties of quantum mechanics, a quantum computer can significantly increase computing power. Even the most powerful supercomputers of today and tomorrow could not match the capabilities of quantum computers.
However, they won’t completely destroy traditional computers. For the majority of issues, using a traditional machine will always be the simplest and most cost-effective option. However, quantum computers hold the potential to drive fascinating developments across a range of disciplines, including materials science and drug research.
Businesses are already experimenting with them to help develop new pharmaceuticals and to make items like lighter and more influential batteries for electric cars.
The secret to a quantum computer’s capability rests in its capacity to generate and control quantum bits, or qubits.
What is a qubit?
Bits are a sequence of electrical or visual pulses that represent 1 or 0 in today’s computers. All of your digital content, including emails, YouTube videos, iTunes music, and tweets, is composed of lengthy sequences of these binary numbers.
On the other hand, qubits—subatomic particles like electrons or photons—are used by quantum computers. Qubit generation and management represent a technical and scientific problem. Certain businesses, like Google, IBM, and Rigetti Computing, use superconducting circuits that are chilled to a temperature lower than that of deep space.
Others, such as IonQ, use ultra-high vacuum chambers to trap different atoms in electromagnetic fields on a silicon chip. Isolating the qubits in a regulated quantum state is the aim in both situations.
Because of some peculiar quantum characteristics, a connected collection of qubits can process information far more quickly than an equivalent amount of conventional bits. Superposition is one of those qualities, and entanglement is another.
What is superposition?
Qubits are able to simultaneously represent a large number of potential combinations of 1 and 0. Superposition is the ability to exist in multiple states at once. Researchers use microwave beams or precise lasers to manipulate qubits into superposition.
This paradoxical occurrence allows a quantum computer with multiple qubits in superposition to process a large number of possible outputs at once. Only until the qubits are measured does the calculation’s ultimate result become apparent, at which point their quantum state instantly “collapses” to either 1 or 0.
What is entanglement?
Scientists are able to produce “entangled” pairs of qubits, in which the two components of the pair exist in the same quantum state. The other qubit’s state will instantly and predictably change in response to changes made to the first one. This occurs even in cases where there is a great distance separating them.
It’s really unclear how or why entanglement operates. Einstein was so perplexed by it that he famously mentioned to it as “spooky action at a distance.” However, the power of quantum computers depends on it. The processing power of a traditional computer doubles with every doubling of its bits.
However, a quantum machine’s capacity to calculate numbers increases exponentially with the number of qubits it possesses because of entanglement.
To function, quantum computers use entangled qubits arranged in a manner akin to a quantum daisy chain. The machines are generating a lot of excitement because of their potential to accelerate computations through the use of specially created quantum algorithms.
What is decoherence?
Decoherence is the state in which qubits interact with their surroundings in a way that eventually causes their quantum behaviour to deteriorate. They are in a highly vulnerable quantum state. Before their task is fully completed, the smallest vibration or temperature shift—disturbances referred to as “noise” in quantum jargon—can lead them to break out of superposition.
For this reason, scientists work hard to keep qubits safe in those vacuum chambers and supercooled refrigerators from the outside world.
However, noise continues to introduce a great deal of mistake into computations despite their best attempts. Some of these can be mitigated by clever quantum algorithms, and more qubits are also beneficial.
To produce a single, extremely dependable qubit—referred to as a “logical” qubit—it will probably take thousands of conventional qubits. This will significantly reduce the computing power of a quantum computer.
The problem is that scientists have only produced 128 conventional qubits thus far (you can view our qubit counter here). Therefore, it will be several years before we see widely applicable quantum computers.
What is quantum supremacy?
It’s the point at which a mathematical computation that is clearly beyond the capabilities of even the strongest supercomputer can be finished by a quantum computer.
The precise number of qubits required to do this remains unknown as scientists continue to develop new algorithms to increase the efficiency of classical machines and as supercomputing technology advances.
However, businesses and researchers are putting a lot of effort into securing the title, conducting tests against some of the most potent supercomputers in existence.
The significance of reaching this milestone is a topic of much discussion in the research community. Companies are already beginning to experiment with quantum computers manufactured by firms such as IBM, Rigetti, and D-Wave, a Canadian company, rather than waiting for dominance to be declared.
Quantum machine access is also being provided by Chinese companies such as Alibaba. While some companies purchase their own quantum computers, others use ones that are made available by cloud computing providers.
Where is a quantum computer likely to be most useful first?
Doing molecular-level simulations of matter behaviour is one of the most exciting uses for quantum computing. Quantum computers are being used by automakers like Daimler and Volkswagen to replicate the chemical makeup of batteries used in electrical vehicles in an effort to uncover new ways to enhance their performance.
Additionally, pharmaceutical firms are using them to examine and contrast substances that may result in the development of novel medications.
Because the machines can quickly process large numbers of possible answers, they are also excellent for optimisation problems. For example, Airbus uses them to assist in determining the aircraft’s most fuel-efficient ascend and descent routes.
Additionally, VW has introduced a programme that determines the best routes for taxis and buses in urban areas to reduce traffic. Additionally, some experts believe that artificial intelligence could be advanced faster by using the machines.
Conclusion
Quantum computing holds the potential to transform computation by solving some kinds of issues that were previously unsolvable. Significant advancements are being made, even though no quantum computer is now complex enough to do computations that a classical computer cannot.
Today, a few major corporations and tiny start-ups have successfully developed non-error-corrected quantum computers made up of several tens of qubits; some of them are even available to the general public via cloud computing. Furthermore, advances in areas ranging from many-body physics to molecule energetics are being made with quantum simulators.