How do quantum computers work?
- Thread starter rosie93
- Start date
Good question
Here at some operations that are built into the "OS" of quantum computers.
Quantum logic gate - Wikipedia
These are the equivalent of logical operations on standard computers.
You use these to build algorithms/
There is a list here:
Quantum Algorithm Zoo
How does that help general computing? If you can map your problem to a QC solution you can take advantage of the speedup.
Algorithm:
Transform your original problem to QC inputs
Init qubit(s)
Do calc (without measuring qubit(s)) - use an Oracle function
Measure qubit(s)
Verify (if possible)
Transform to solution of original classic problem
Verify (if cheap - e.g. NP)
By doing your calc in superposition you move the complexity of the solution further up this table.
-
This is a Hello World QC program
How To Solve A Problem With Quantum Computing
This is a good lecture:
-
DWAVE used quantum properties to implement a QC low point landscape function, which could theoretically be used for NP+ hard problems. I'm not sure if they used the above logical QC "instruction set".
-
Like back in the 60's with classical computers, with current QC's you need to understand physics, engineering, math(s) and comp sci
now i could be way off. but the way superposition seems to work and how they explain quantum computing and real world problems. it seems to me that we're only at the stage of asking the QC a question while giving it something with many possibilities, looking for 1 answer. we're not yet at the point where we are trying to create our own worlds or tell it what to do as we are with classical computers. If this is, that, then do that other thing, else do something else. is where we are with classical computers.
but as of now, i would think you could use a quantum computer to calculate some of our problems within your classical computer created code. i'll give you an example. lets use video games. specifically sports games, more specifically basketball physics. no game has to my knowledge ever done a great job of creating true basketball physics. we're just talking about the ball bouncing off the floor back to a players hands, going thru the net, hitting the backboard bouncing off at different angles. being passed thru the air from one start point and ending at another. there are probably millions of angles a spots on the backboard a jump or layup can hit the backboard. then there are probably just as many possibilities to where will that ball land once it hits the backboard in said spot. to do this computation in classical computers you would run out of memory/ram etc. but perhaps if there was some way you like a GPU, you could send that part of your code to a mini quantum computer. allow it to run the possibilities, and bam come up with one answer..the ball bounces off from this point at this angle at X speed. true physics of a basketball in a video game. shoot, i may have just come up with something. (c)rapbeats tm. lol
now some may wonder, well what do classical computers do now for that same basketball physics without the help of quantum calculations/or a quantum computer?
from my knowledge. they can take one of 3 approaches.
1. try to use actual physics but place a hard cap on how many solutions are to their answer of at what angle will the ball bounce off the backboard and at what speed will it come off said backboard. this would keep the answer to a small enough number of options to not blow the ram or blow up your memory and have the game freeze on you. but this also means you will miss out on all of the actual possibilities that would be there in real life. and because we've seen the real thing before we will notice when the game just picks something close but not close enough to what should have happened based on the angle where the ball hit the backboard the first time.
2.completely cheat and force the ball to bounce off at certain angles that SEEM to be realistic visually but may or may not be realistic to actual physics if it were to occur. this will look just fine until you start to pay close attention. and notice the cpu and programming will FORCE the ball into certain directions when it was never going that way. at times the game will look completely fake thanks to this. See 2k's basketball game for something like this.
or #3. a combination of both 1 & 2. See NBA live's last and first real attempt at basketball physics. NBA ELITE 11(the game that everyone clowned on for bad graphical reasons, but only a select few understood what EA at the time was trying to do.which was something ground breaking.
Last edited:
well never say long ... because thanks to tech, it speeds itself up. more tech begets more tech. wash rinse repeat. and it keeps speeding up the timeline. but you're correct about us building things we dont full understand and could easily kill us all or harm us in other ways. but shoot, we could say the same for basic tech like cars and planes, trains, all that CO2 released into the air. who knew? no one at first. sure i know some of these major car and oil companies figured it out and still hid the info. but i'm talking about before that. who knew? no one.
so basically anything outside of the basics of living off the land like we use to. with a couple of sticks and stones. than we will always be behind our own creations or always missing something that we just didnt see coming. this is what makes us human and not God. we dont truly know every single thing about our own creations. we just cant. we dont have that ability.
null
...
yeah more or less . QC is around the instruction set / machine code level. the problems it is suited for are algorithmically expensive problems and fundamental algorithmic problems.
this book has tons of examples - The Art of Computer Programming - Wikipedia.
my guess is that they would approach the fundamental problems first (along with the easy wins). that means classical discrete type problems at core with some more applied stuff thrown in.
problems map from O(1) constant to undecidable. In those classes there is set of problems which are decidable but which are intractable because of time / space. There are other problems which are tractable but too slow for practical purposes.
these are the class of problems where most benefit has to be gained. but we have to figure out first how to map classical problem solutions onto a set of qubit operations.
