Quantum computers turn out to be far less useful than originally thought

Retro

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This is really disappointing. You know how the quantum computer revolution seems to be permanently a few decades away? Well, now that more is known about how they work and that peculiar quantum superposition of qubits that makes them, well, quantum, it turns out that the big, exponential advantages only happen with certain, very specialised types of problem, because trying it out on other types of problem just results in gibberish, or only a little output data which isn't very useful. This means that there won't be general purpose quantum PCs sitting on our desks or in smartphones, replacing the classical versions we have now, as they're only good at certain things. So, for example, we won't be getting next gen games with human-like AI in them as there's no quantum advantage to exploit there. Indeed, we already have that to a degree nowadays with classical computers and it's only gonna get better.

However, the certain things that they are good at are worth perservering with, so they're not going away and will only get better with time.

Mithuna Yoganathan, who has a PhD in theoretical physics at the University of Cambridge, explains all this in simple language that we can all understand.

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AllThingsTech

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Well they can be critical for the wrong reasons, such as breaking encryption typically used - asymmetric public key encryption! Quantum computers are powerful enough to efficiently perform the mathematical operations sufficient to break current encryption algorithms.

The government have a plan to migrate from modern encryption to Post Quantum Encryption, to be completed by 2031 for all services.

I’m concerned about cyber-security in companies not being taken seriously as they should be, as I’d mentioned in the thread about software bugs. As @Retro and I’d discussed, companies always prioritise profits over compliance with laws, with the shit load of corruption! I’m concerned that quantum computers will break into an entire stream of companies. Here’s to a series of cyber attacks, I certainly hope not! 😡
 
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Retro

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Yes, ironic that the one thing they're really good at is the thing that one would really rather they weren't. :(
 

Retro

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I dunno what's with that site. It always unfurls to just show MSN, although the link does point to the correct article. That's why I try not to link to anything there if I can avoid it.
 

AllThingsTech

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Well, while errors related to natural law, such as decoherence (the natural decay of the quantum state) and leakage (the qubit state leaking out of the computational subspace), can be reduced only within those laws, scientists have achieved error rate to one error per 6.7 million operations by reducing the noise generated by the computer's architecture and control methods to almost zero; previously the same team demonstrated an error rate of approximately one error for every 1 million operations.

https://www.livescience.com/technology/c...r-machines

In essence, the researchers developed an algorithm to detect and correct the noise produced by the microwaves used to trap the ions; using this method, it is now possible to develop quantum computers that are capable of conducting single-gate operations (those conducted with a single qubit gate as opposed to a gate requiring multiple qubits) with nearly zero errors at large scales, given that won't have to dedicate as many qubits to the sole purpose of error correction.

However, many quantum algorithms still require multigate qubits functioning alongside or formed from single-gate qubits to perform computations beyond rudimentary functions. In spite of this, the error rate in two-qubit gate functions is roughly 1 in 2,000.
 
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