7 ms·

Why is an assembly line needed for a type of computer that has never done a useful calculation?

by PopePompus 3y ago

rbanffy 3y ago
I believe IBM has shown an actual usage example in chemistry simulation.
- varelse 3y ago
  [dead]
bowsamic 3y ago
As a quantum physicist myself, this is a very good question. I remember going to a quantum control conference (a topic very relevant to quantum computing) a few years ago and there were a couple of quantum computing startups. I asked their engineers, what exactly are quantum computers useful for? They had no concrete ideas. I don't think the situation is much better today. Now, I understand building quantum computers in research settings, even if just for the secondary theoretical and technological outcomes of learning how to build them (similar to how creating gravitational wave detectors led to a greater development of seismometers, quantum noise theory and techologies, control systems, etc.) However, I honestly can't wrap my head around the value proposition for companies to make these things. The only cases I can see is making them in order to sell to research groups who want to use them to implement quantum communication strategies and basic quantum simulations. On second thought, that might be enough, but it is a very small market.
- garyiskidding 3y ago
  I did not understand what real world computing use would quantum computers have over the current generation of compute in terms of architecture/efficiency or a measurable metric. Thanks for explaining.
  - bowsamic 3y ago
    The main benefit of quantum computers is that they're (in principle) very precisely controllable quantum systems. In a sense, if you do a "quantum simulation", it's actually physically real since you are actually working with the same quantum states and interactions you would have in the "real thing". Apart from some strange cases (usually using quantum fourier transform, such as prime number factorisation) they are not good replacements for classical computers at all.
- n4r9 3y ago
  As I understand from Wikipedia there are four fundamental quantum algorithms that perform better in some way than the best-known classical counterparts, and many more algorithms in total. The four fundamental ones are: * HHL algorithm for solving (sparse & insensitive) systems of linear equations * Grover's search algorithm for determining black-box inputs * Shor's algorithm for factoring primes * Quantum fourier transforms The above have various potential applications such as: * Deep learning [0] * Finance [1] * Solving large-dimensional differential equations [2] * Solving constraint satisfaction problems [3] I also came across a webpage called Quantum Algorithm Zoo [4] which looks like it answers your question in much more detail. [0] https://arxiv.org/abs/1806.11463 https://arxiv.org/abs/1806.11463 [1] https://www.google.com/books/edition/Quantum_Machine_Learning_and_Optimisatio/22SXEAAAQBAJ?hl=en&gbpv=1&pg=PA349 https://www.google.com/books/edition/Quantum_Machine_Learnin... [2] https://arxiv.org/abs/1512.05903 https://arxiv.org/abs/1512.05903 [3] https://link.springer.com/article/10.1007/s002000050134 https://link.springer.com/article/10.1007/s002000050134 [4] https://quantumalgorithmzoo.org/ https://quantumalgorithmzoo.org/
  - varelse 3y ago
    [dead]
  - okintheory 3y ago
    You should be very skeptical of all those applications except Shor. HHL: Here's a quote from Ewin Tang [1]: "We know that quantum computers can “efficiently solve” high-dimensional linear algebra problems; however, this assumes that we have some way to evolve a quantum system precisely according to input data, a much harder problem than the linear algebra itself." [1] https://ewintang.com/blog/2019/01/28/an-overview-of-quantum-inspired-sampling/#fn:hhl08 https://ewintang.com/blog/2019/01/28/an-overview-of-quantum-... Grover's search: This is a speed-up from 2^n to 2^sqrt(n). Impressive, but there's not a lot of exp-time algorithms that people ever run. They go for heuristics instead. Quantum fourier transforms: This is a tool, it's cool, but needs an application. I haven't seen a serious proposal for using it somewhere where a classical algorithm wouldn't do better.
    - 3y ago
skywhopper 3y ago
Investors are impatient, and talk of assembly lines and manufacturing signals to them that an actual product is near. I suspect it’s mostly smoke and mirrors to keep the funding flowing for a few more years.

Why is an assembly line needed for a type of computer that has never done a useful calculation?

rbanffy 3y ago

I believe IBM has shown an actual usage example in chemistry simulation.

varelse 3y ago
[dead]

bowsamic 3y ago

As a quantum physicist myself, this is a very good question. I remember going to a quantum control conference (a topic very relevant to quantum computing) a few years ago and there were a couple of quantum computing startups. I asked their engineers, what exactly are quantum computers useful for? They had no concrete ideas. I don't think the situation is much better today. Now, I understand building quantum computers in research settings, even if just for the secondary theoretical and technological outcomes of learning how to build them (similar to how creating gravitational wave detectors led to a greater development of seismometers, quantum noise theory and techologies, control systems, etc.) However, I honestly can't wrap my head around the value proposition for companies to make these things. The only cases I can see is making them in order to sell to research groups who want to use them to implement quantum communication strategies and basic quantum simulations. On second thought, that might be enough, but it is a very small market.

garyiskidding 3y ago
I did not understand what real world computing use would quantum computers have over the current generation of compute in terms of architecture/efficiency or a measurable metric. Thanks for explaining.
- bowsamic 3y ago
  The main benefit of quantum computers is that they're (in principle) very precisely controllable quantum systems. In a sense, if you do a "quantum simulation", it's actually physically real since you are actually working with the same quantum states and interactions you would have in the "real thing". Apart from some strange cases (usually using quantum fourier transform, such as prime number factorisation) they are not good replacements for classical computers at all.
n4r9 3y ago
As I understand from Wikipedia there are four fundamental quantum algorithms that perform better in some way than the best-known classical counterparts, and many more algorithms in total. The four fundamental ones are: * HHL algorithm for solving (sparse & insensitive) systems of linear equations * Grover's search algorithm for determining black-box inputs * Shor's algorithm for factoring primes * Quantum fourier transforms The above have various potential applications such as: * Deep learning [0] * Finance [1] * Solving large-dimensional differential equations [2] * Solving constraint satisfaction problems [3] I also came across a webpage called Quantum Algorithm Zoo [4] which looks like it answers your question in much more detail. [0] https://arxiv.org/abs/1806.11463 https://arxiv.org/abs/1806.11463 [1] https://www.google.com/books/edition/Quantum_Machine_Learning_and_Optimisatio/22SXEAAAQBAJ?hl=en&gbpv=1&pg=PA349 https://www.google.com/books/edition/Quantum_Machine_Learnin... [2] https://arxiv.org/abs/1512.05903 https://arxiv.org/abs/1512.05903 [3] https://link.springer.com/article/10.1007/s002000050134 https://link.springer.com/article/10.1007/s002000050134 [4] https://quantumalgorithmzoo.org/ https://quantumalgorithmzoo.org/
- varelse 3y ago
  [dead]
- okintheory 3y ago
  You should be very skeptical of all those applications except Shor. HHL: Here's a quote from Ewin Tang [1]: "We know that quantum computers can “efficiently solve” high-dimensional linear algebra problems; however, this assumes that we have some way to evolve a quantum system precisely according to input data, a much harder problem than the linear algebra itself." [1] https://ewintang.com/blog/2019/01/28/an-overview-of-quantum-inspired-sampling/#fn:hhl08 https://ewintang.com/blog/2019/01/28/an-overview-of-quantum-... Grover's search: This is a speed-up from 2^n to 2^sqrt(n). Impressive, but there's not a lot of exp-time algorithms that people ever run. They go for heuristics instead. Quantum fourier transforms: This is a tool, it's cool, but needs an application. I haven't seen a serious proposal for using it somewhere where a classical algorithm wouldn't do better.
  - 3y ago

skywhopper 3y ago

Investors are impatient, and talk of assembly lines and manufacturing signals to them that an actual product is near. I suspect it’s mostly smoke and mirrors to keep the funding flowing for a few more years.