What can quantum computers do more efficiently than regular computers

The answer is no. We cannot be 100% certain. Just like we don't have a proof that P $\ne$ NP, there is no proof that NP $\ne$ QMA, though we believe both these inequalities to be true even without proof. Furthermore, we do not know how the "engineering complexity" scales, so even though Shor's algorithm has exponentially fewer operations to perform than the best known classical algorithm, it might be double exponentially more difficult to implement it physically. See my answer to this question: It is also possible that there exists a proof that NP $\ne$ QMA and that the engineering complexity scales linearly, meaning that quantum computers could "provably" have some advantage, but we just do not know of any such proof yet. Until we see a quantum computer give these "huge improvements" for a problem where it is provably better than the best classical algorithm, we have no way of being 100% certain that quantum computers will provide what you ask. Quantum communication though (not necessarily quantum computing), does have some provable benefits over present day classical communication devices, and one example is the BB84 protocol. $\begingroup$ If the question is whether quantum computers will provably bring an advantage, the more likely class of problems to consider is BQP (problems which polynomial-uniform quantum circuits can decide with bounded error) rather than QMA (yes/no problems for which candidate answers, possibly obtained by some completely other means, have proo...

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Closed 2 years ago. I feel the answer to this question is just out of reach - I "understand" the implication that a quantum computer uses all combinations of bits simultaneously compared to a classic computer, and that clearly gives a huge boost to processing times, however I'm struggling to quite grasp how. I watched So to try and get my head around it, I decided to compare this to my PC. Forgetting memory needed for anything other than storing combinations, if I have 16GB of RAM available, that's 2 17'179'869'184 possible combinations, or ~57 million lots of 53 bits (with each one in one specific combination). So for each cycle of combinations, my PC is able to hold ~57 million combinations of 53 bits, and if my PC is running at 4.1GHz, that's 7.0E+19, or in the region of 2 66 combinations per second. Now I have a good PC, but it seems to be reasonably on a par with Google's quantum computer, which just seems wrong. I know that I've not used an exact science to calculate things but I can't follow where I've screwed up the maths? The claim for the 300 qubit QC I also can't follow with the above logic. As excel won't work with stupidly large numbers I tried to do this on paper, so bear with me: There are 10E+80 atoms in the universe, so this number of bits would give 2 (10E+80), or 2 800 combinations. An unholy number that no-one could possibly comprehend. For the QC there are 300 qubits or ~2 8 therefore one could store 2 792 combinations at any one time, which is already...

Quantum computing is a rapidly-emerging technology that harnesses the laws of quantum mechanics to solve problems too complex for classical computers. Today, IBM Quantum makes real quantum hardware -- a tool scientists only began to imagine three decades ago -- available to hundreds of thousands of developers. Our engineers deliver ever-more-powerful superconducting quantum processors at regular intervals, alongside crucial advances in software and quantum-classical orchestration. This work drives toward the quantum computing speed and capacity necessary to change the world. These machines are very different from the classical computers that have been around for more than half a century. Here's a primer on this transformative technology. For some problems, supercomputers aren’t that super. When scientists and engineers encounter difficult problems, they turn to supercomputers. These are very large classical computers, often with thousands of classical CPU and GPU cores. However, even supercomputers struggle to solve certain kinds of problems. If a supercomputer gets stumped, that's probably because the big classical machine was asked to solve a problem with a high degree of complexity. When classical computers fail, it's often due to complexity Complex problems are problems with lots of variables interacting in complicated ways. Modeling the behavior of individual atoms in a molecule is a complex problem, because of all the different electrons interacting with one another....

Published: 14 Dec 2022 As new technologies develop and gain traction, the public tends to divide into two groups: those who believe it will make an impact and grow, and those who don't. The former tends to be correct, so it is crucial to understand how future technologies differ from the status quo to prepare for their adoption en masse. Classical computing has been the norm for decades, but in recent years, quantum computing has continued to rapidly develop. The technology is It might be years before widespread implementation of quantum computing. However, explore the differences between classical vs. quantum computing to gain an understanding should the technology become more widespread. Differences between classical computing vs. quantum computing Quantum computers typically must operate under more regulated physical conditions than classical computers because of quantum mechanics. Classical computers have less compute power than quantum computers and cannot scale as easily. They also use different units of data -- classical computers use bits and quantum computers use qubits. Units of data: Bits and bytes vs. qubits In classical computers, data is processed in a binary manner. Classical computers use bits -- eight units of bits is referred to as one byte -- as their basic unit of data. Classical computers write code in a binary manner as a 1 or a 0. Simply put, these 1s and 0s indicate the state of on or off, respectively. They can also indicate true or false or yes or...