A new quantum computer can execute calculations in mere moments that would take the most advanced supercomputers 47 years to process.

  • hetscop@kbin.social
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    1 year ago

    This is article is missleading about how quantum computing works.

    Superposition increases the computing power of a quantum computer exponentially. For example, two qubits can exist in four states simultaneously (00, 01, 10, 11), three qubits in eight states, and so on. This allows quantum computers to process a massive number of possibilities at once.

    Quantum computers aren’t faster because they “process” multiple “possibilities” at once. Quantum computers aren’t any faster than regular computers when it comes to general purpose computing. You can exploit some interesting properties about quantum computing to solve certain problems asymptotically faster, like with Shor’s algorithm.

    This means that the time to solve a problem as the size of the problem grows scales better. Using Shor’s algorithm, the time to factor a polynomial is proprtional to (log N)^2 log log N, where N is the size of the input data, instead of the fastest known non-quantum algorithm which takes time proportional to e^(1.9(log N)^(1/3)(log log N)^(2/3)). Note that the majority of problems that we would maybe like to solve using a computer don’t have any fancy quantum algorithms asociated with them and as such are no faster than a normal computer,

    Given a large enough problem that can be solved with a quantum algorithm, a quantum computer will eventually outperform a non-quantum computer. This does not mean that quantum computers can solve arbitrary problems quickly.