Quantum computer

Quantum computers use quantum-mechanical phenomena such as superposition and entanglement to perform computation. These are able to solve certain computational problems, such as integer factorization (which underlies RSA encryption), substantially faster than classical computers.

Binary code represents information as either a 0 or 1, and these traditional von Neumann architecture computers are better at serial processing. Quantum computers are better at parallel processing because they use qubits, which are simultaneously both 0 and 1. Qubits are formed by the quantum states of particles, for example, the spin state of individual electrons. This superposition of states allows a quantum computer to test every possible combination of qubits at the same time. A thousand-qubit system could test 21000 potential solutions in the blink of an eye, thus vastly outperforming a conventional computer. To get a sense for the magnitude of 21000 (which is approximately 10301), note that there are only about 1080 atoms in the visible universe. The current world record is China's Zuchongzhi processor at 66 qubits with a magnitude of 266.

Time crystals are used to stabilize qubits. They are resistant to entropy and can be used for quantum memory. A time crystal was recently observed by Google.

Applications suited to a high degree of parallelism:


 * Quantum entanglement and modelling for quantum teleportation systems.
 * Computational chemistry, for example a new drug R&D program is trial and error, iterative, time-consuming and expensive.
 * Particle physics workflows such as needed for colliders; quantum chromodynamics and quantum physics.
 * Molecular modeling such as in chemical reactions that are quantum in nature, forming entangled quantum superposition states.
 * Global weather prediction and modelling. 30 percent of world GDP is directly or indirectly affected by weather, impacting food production, transportation and trade. Another benefit is giving ourselves time to take cover from disasters.
 * Artificial Intelligence and Machine Learning, based on calculating the probabilities for many possible choices.
 * Cybersecurity and cryptography. New quantum-resistant cryptography methods would be needed that would resist quantum computers able to crack the old prime factorization methods.
 * Financial Modelling and stock markets. Randomness inherent to quantum computers is congruent to the stochastic nature of financial markets. Investors often wish to evaluate the distribution of outcomes under an extremely large number of scenarios.
 * Combinatorics and set theory
 * Chaos Theory
 * Simulating the electronic structure of a small molecule

A potential problem for traditional encryption such as those used in cryptocurrency or even the strongest as at 2021 - AES - is that quantum computers are able to crack them. Math problems (like the ones encrypting our sensitive data today) that would take a traditional computer billions of years to solve can be solved by quantum computers in a matter of seconds. People with malintent are harvesting encrypted data today to decrypt later with quantum computers. In the near future once quantum computing is mainstream, they will be used to breach cryptographic defences.

Two ways of circumventing this problem would be to create traditional encryption algorithms that are quantum resistant, or adopt quantum encryption algorithms that would be impossible for traditional or quantum computers to crack. Quantropi claims to be one of the world's first companies to offer the latter method with their non-photonic quantum key distribution that works over the cloud - so clients are able to use existing infrastructure and the internet to encrypt their sensitive information into quantum states of entropy. Quantropi’s QEEP symmetric encryption ensures "uncertainty" to attackers, rendering data uninterpretable forever. They also provide a quantum-secure layer to AES encryption.

A quantum computer using nanotechnology is a moleculartronic computer.

Current fastest quantum processors that have achieved quantum supremacy (the point at which quantum computing can solve a problem that would take an impractical time for classical computing):


 * Google's Sycamore processor - 53 qubits
 * China's photonic Jiuzhang - 53 qubits
 * China's Zuchongzhi processor - 66 qubits (link)