## What is the diference between classic probabilities and quantum probabilities?

-1

So, I'm really trying my best to understand how quantum computers work.

This is how I think they work:

1. There is a set of qubits;
2. Then an algorithm is put in action by the use of quantum gates that entangle these qubits and rotate them in a way to produce equal probabilities for each case (like for example in a big list of items);
3. At this moment the way I visualize things is like a series of ball spheres that individually act as layers that have some information relative to each case, but combined they are like a single ball sphere that has more information on it (something like photoshop layers, but in 3d);
4. Until this point everything seems like something that I could build in a classic computer, the difference is that in everything I read it is told to me that quantum computers do not go through all of the possibilities, but only some, as they are probabilistic. Ok, but if the probabilities start by being equal to each case, how can one find the right cases?
5. I read that it is by the use of phase and interference, and this is where there is lack of information and where I stop to understand how quantum computers work;
6. And then, in the end, qubits are collapsed so we get actual values in ones and zeros coming from those previous probabilities;

Please, try to explain with simple terms and examples like I just did, more than this will be like what's out there, complicated and not useful, or to simple and repetitive.

It's about time someone explains quantum computing in simple ways. Why complicate what's not so complicated? If one is unable to explain how things work, and sometimes people actually working on the field, how can this technology progress? Still, I will appreciate any efforts to help me understand this technology.

If you want to use formulas and functions go ahead, but please, completely explain what they do...

Question was closed 2019-12-12T00:12:13.703

The thing about quantum computing is that the English language is neither precise nor sufficient to explain it to a layman. The bare minimum you need to learn the subject is linear algebra and some high school physics. And we don't have sufficient bandwidth to provide you extensive courses on those topics, here. Could recommend a few textbooks though. – Sanchayan Dutta – 2019-12-11T22:03:47.120

I don't need to understand all concepts revolving around this subject, I just need some simplification of what actually happens... at least on this part relative to the probabilities. I will not dispense your books recommendations though... – fabiolinhares – 2019-12-12T00:03:13.663

Every subject requires some foundational concepts. You can't really understand long division without knowing addition/subtraction. As for textbook recommendations, there are already plenty on this site. Try googling a bit. – Sanchayan Dutta – 2019-12-12T09:01:11.543

I know all fundamental concepts by reading Wikipedia, search images on google, and watching very explanatory videos on youtube. There is only a lack of explanation on this probability part. I already understand the in-phase and out-of-phase part of the waves. But I what to go from these joining and cancelation of some parts of the waves to how one arrives to a skewed result towards the right answer/case. – fabiolinhares – 2019-12-12T22:16:37.163

1

It is not very easy to explain how a quantum computer works. Your question is very broad. It can take even whole book to explain everything you want to know clearly, so this forum is probably not the best place to do so.

I would recommend reading this book: Hidden In Plain Sight 10: How To Program A Quantum Computer.

I am self learner in quantum computing and this book helped me much to understand basics. It cost only \$1.2 in Kindle format.

thanks again for you answer. This book probably has complex terminology and explanations... Could you please do one attempt at trying to explain at least this part related to interference and probabilities? The way I understand this interference is like: a particle should have one path, but what happens is that there are many interference's on this path along the way, and this gives the programmer all the path possible, but skewed toward the right case. – fabiolinhares – 2019-12-12T00:14:04.957

@fabio I don't understand the complaint about "complex terminology and explanations". Sure, there will be some new terminology and concepts but if you really want to understand the subject you need to invest a few days of your life into understanding those. There might be a ELI5 explanation out there but it's bound to be handwavy and I'm not sure you'd be satisfied with yourself with a superficial understanding of the subject. (BTW, your explanation of interference doesn't make much sense and isn't on the right track.) – Sanchayan Dutta – 2019-12-12T09:05:47.520

https://www.youtube.com/watch?v=GzbKb59my3U - from this point on I just wanted to understand how one arrives to actual probabilities – fabiolinhares – 2019-12-12T22:03:54.837