A classical computer performs operations using

classical bits, which can be either zero or one. Now in contrast, a quantum computer users

quantum bits or qubits. And they can be both zero and one at the same time. And it is this

that gives a quantum computer its superior computing power. There are a number of physical objects that

can be used as a qubit. A single photon, a nucleus or an electron.

I met up with researchers who were using the outermost electron in phosphorous as a qubit.

But how does that work? Well, all electrons have magnetic fields, so they are basically

like tiny bar magnets. And this property is called spin. If you place them in a magnetic

field they will align with that field, just like a compass needle lines up with the magnetic

field of the earth. Now this is the lowest energy state, so you

could call it the zero state or we call it for the electron, spin down. Now you can put

it in a one state, or spin up, but that takes some energy.>>If you took out the glass from your compass

you could turn the needle the other way, but you would have to apply some force to it.

You have to push it to flip to the other side. And that is the highest energy state. In principle,

if you were so delicate to really put it exactly against the magnetic field, it would stay

there.>>Now so far this is basically just like

a classical bit. It has got two states, spin up and spin down, which are like the classical

one and zero. But the funny thing about quantum objects is that thy can be in both states

at once. Now when you measure the spin it will be either up or down. But before you

measure it, the electron can exist in what is called a quantum super position, where

these coefficients indicate the relative probability of finding the electron in one state or the

other. Now it is hard to imagine how this enables

this incredible computing power of quantum computers without considering two interacting

quantum bits.>>Hello.

>>Hi. Now there are four possible states of these

two electrons.>>You could think that, well, that is just

like two bits of a classical computer, right? If you have two bits you can write zero, zero;

zero, one; one, zero; one, one. Right? There is four numbers. But these are still just two bits of information.

Right? All I need to say to determine which one of the four numbers you have in your computer

code is the value of the first bit and the value of the second bit. Here, instead, quantum

mechanics allows me to make super position of each one of these four states. So I can

write a quantum mechanical state, which is perfectly legitimate, that is some coefficient

times this plus some coefficient times that plus some coefficient times that plus some

coefficient times that. So determine the state of this two spin system,

I need to give you four numbers, four coefficients, whereas in the classical example of the two

bits, I only need to give you two bits. So this is how you understand why two qubits

actually contain four bits of information. I need to give you four numbers to tell you

the state of this system, whereas here I only need two. Now if we make three spins, we would have

eight different states and it could give you eight different numbers to define the state

of those three spins, whereas classical it is just three bits.

If you keep going, what you find is that the amount of equivalent classical information

contained by N qubits is two to the power N classical bits. And, of course, the power of exponentials

tells you that once you have, let’s say, 300 of those qubits in what we call the folient

angle state, so you must be able to create these really crazy states where there is a

super position of all three angles being one way and another way and another way and so

on, then you have like two to the 300 classical bits, which is as many particles as there

are in the universe.>>But there is a catch, although the qubits

can exist in any combination of states, when they are measured they must fall into one

of the basis states. And all the other information about the state before the measurement is

lost.>>So you don’t want generally to have as

the final result of your quantum computation something that is a very complicated super

positional state, because our cannot measure a super position. You can only measure one

of these basis states.>>Like down, down, up, up.>>Yeah. So what you want is to design the

logical operations that you need to get to the final computational result in such a way

that the final result is something you are able to measure, just a unique state.>>That is not trivial.>>That is not trivial. And it is essentially

… I am kind of stretching things, but I guess it is to some degree the reason why

quantum computers are not a replacement of classical computers.>>They are not.>>No, they are not. They are not universally

faster. They are only faster for special types of calculations where you can use the fact

that you have all these quantum super positions available to you at the same time, to do some

kind of computational parallelism. If you just want to watch a video in high definition

or browse the internet or write some documenting work, they are not going to give you any particular

improvement if you need to use a classical algorithm to get the result. So you should

not think of a quantum computer as something where every operation is faster. In fact,

every operation is probably going to be slower than in the computer you have at your desk.

But it is a computer where the number of operations required to arrive at the result is exponentially

small. So the improvement is not in the speed of the individual operation. It is in the

total number of operations you need to arrive at the result.

But that is only the case in particular types of calculations, particular algorithms. It

is not universally, which is why it is not a replacement of a classical computer.

so in simplified terms.. its a complex software that is easy to use when solving really really complex problems, and it saves time as its faster than a normal computer..If its a simple problem a normal computer will solve things much faster

Is that Nicolas cage?

when i saw those 0.xx numbers with the electron pointing both up and down i understood the whole concept immediately, because it reminded me of cells in neural networks.

Thanx Veritasium, Finally understood the concept after watching the video several times.

Mum: HOW DO YOU EXPLAIN GETTING A ZERO IN YOUR EXAM!!?

Me: Relax Mum. My test paper is quantum state. It's both a 0 and 100 at the same time. Just measure it again and you'll see I actually got a 100 😉

Internet: YOU FOOL! THE POSSIBLE STATES ARE NOT BINARY ….

Me: Shut the …

is space an illusion ?

ok

can you guys please speak in 'english' ??

In. Future… It will be CPU GPU n QPU

2:51 Can someone please explain this diagram please?

So basically, quantum computing allows you to have a ton of information with less bits, the main problem is however, you can't really get that information until the algorithm is done… got it!

Man there are some clever mofo’s out there.

0:40 Ping!

0:57 Ping!

I started to understand from 5:15

you need 2 ^ 300 numbers as coefficients, to "define" one of possible states of 300 qubits. Now, where do you store those 2 ^ 300 numbers in?

The first time I’ve seen it explained without the hype. I wish he had an actual use case as an example. Perhaps how it will compute 1+1 =2.

Quantum Computing Class Final:Professor:"Ok, did everyone hear our silly explanation of how quantum computing works? I mean in theory at least?"Everyone in the class:"Yes professor."Professor:"Ok, you all Pass!"Looks useless, I wonder if the tech improved in the last 5 years tho.

absolutely mad scientist crazy! annihilation !!! even I understand!

ok so you have to design the quantum computer in such a way that you predict the qbits value at given time of use?

so smart yet so unwise to not shave that little dog off his chin .

the summary:

the quantum computation – for now- can be used only for huge amount of data processing but can not be translated into our classical computational systems

that means we need an inter-translation system to connect between both worlds

I believe that what are we going to see in the near future

This is what Shaggy is doing for life nowadays. Feel old yet?

Quantum physics show come back on those who practice quantum physics they shall be entangled by their own Quantum ism

885 persons are pissed off that the quantum computer is not faster than the classical computer.

The perpetual parroting of "…cubits can be both 0 and 1 at the same time…" might sound intriguing but sadly makes no sense and isn't the case at all. A clear explanation still has to appear on the net. The error in the illustration of the 4 possible states at 2:01 adds to the confusion (gamma & beta).

Nice to know ones limitations.

Where did you get that awesome P costume? I want one for Halloween!

If you set your computer code in a quantum state on a quantum computer, then it would be next to impossible to hack into it. Do i have that right?

So it works like a tri state output ? So its linear ?

spin down

bingWhat is a magnetic field made of ? Vacuum wind ?

So we get a superposed answer ?

As clear as mud …

Google has created the first Quantum Computer today!

Hmmmm…I see

Excellent explanation.

I have a quantum understanding of this. I both get it and don't get it at the same time.

Well either quantum computers are better then binary or they are not. Maybe they are both.

Not very well explained…

electrons and polarity, ok I can understand that

then you add alpha, beta, gama, delta… what are this ?!?

Is our brain a quantum computer

What?

?

Look at this: It means that the set of classical algorithms admitting quantum speeding up has probability measure zero. __ https://arxiv.org/abs/quant-ph/9803064 ___So, SOME problems quantum comp will do much faster, like password cracking… In fact quantum comp is based on probability. It means that it can calculate something true with probability…99.2%. That is all. So, how will we protect our passwords?:)

midnight train to georgia

What is the background music?

If I understand correctly (sure), you start with a vague question and if the qubits are superpositioned in every possible state, every possible answer your computer could give is already there. So it's kind of like trying to have the largest pool of answers possible to draw from, so the answer can be as accurate as possible. Imagine asking someone to guess a number between 1 and 10 and they respond with 3.58, where you saw ten possible answers, they saw a thousand. After that, your supposed to go with the most probable answer, but I'm not sure how that measuring is accomplished, since just measuring forces the qubits out of superposition.

Now I have a nose bleed, and my brain hurts….owe

I lost it at 2:00 how did he manage to do that?

These guys are idiots

Thank you for the clear explanation!

I feel like I understand some of it but it leads me to think that an entangled pair don't communicate at all they simple have a fixed relationship. So by knowing the state of one in the pair you know the state of the other. But this only works on a given moment in time. After that moment the second one continues to move and change thus without knowing it's period of change you have a 50/50 chance of which state it is in if measured later.So the spooky action at a distance just seems like it is another piece of data being time. But how could it be this simple and not have been noticed by someone other than me?

Best explaination till this date!

If you people believe in quantum this and quantum that you are a bunch of retards!

Explain it to me like im five. – Michael Scott hahaha

Its like explaining Calculus to a stone age human. How on earth do these people even communicate with the sub atomic particles or whatever and get them to work?. mind bogging

Quantum conputing is a theory based delusion. So its important nobody understands. So they can fool people.

Morello is providing his doubts, only true scientist does that, I like it

a quantum bit ie a unit of light cannot be a one and zero at the same time.

light is polarized, meaning it has its own magnetic field, a computer uses

magnetic fields to name bits ones or zeros, a bit or unit cannot be both a

one and a zero at the same time. what this is speaking of are fallen angels

who are androgynous, ie both sexes, female body, male genitals.

Could you please explain how we can detect these spins? It seems we need very sensitive sensors to determine the spin of the electron

what kind of math is this exactly? [I really need to know this, or i'm getting steamrolled by the teacher]

Doesnt that mean that they could create super defense systems against malware? Making hacking impossible with a normal computer? Idk

Wow! I’m a bit shocked, because today i had a lecture in the university about the quantum superposition! Is it a coincidence that i have this video in my recommendation list?

It doesn't.. 😂

i wonder if it could handle minecraft with ray tracing

"They can be a zero or a one at the same time"

I don't get it.

The guy explaining is in a super position of human. he is in Both Male and Female form at the same time 🙂

Нихуя не понял, но очень интересно.

mid 2013

Is because of overheating?

I think so.

It looks very awesome interesting to me but takes much of your mind i did not get athing

is there any sane reason why you constantly move the camera, when you record Andrea? thumbs down for one of the worst cameraman.

Another video about quantum computing that doesn’t fulfill its promise :/

"2 to the dree hundred classical bits ah ah ah" – Sesame street's The Count.

the comments on these type of videos are so funny cus its too true

2:50, does this suggest that a multiverse simulation would be possible in the near future

very well explained. thank you.

1:40 finally got it here after watching so many videos… these few seconds made it

He does a great job at explaining it. Picks his words with great care. Now I want to know which types of calculations would benefit from quantum computing.

Not understanding this makes me really mad.

Totally forgot I was watching this. Thank god for smart people.

can the camera man stay still omg

What

who's here after Google released their first quantum supremacy ?

Wtf did he just say!

My brain just shattered in a million places.

That's why he makes the big bucks

Dammit I should have hung out with geeks! lol

who is here after google quantum supremacy claim

Thank God my job is safe…ufff

lecture is out of my skull

100% of people who watched the video understood everything but the other 100% of them didnt understand anything

and thats called a superpositionWhat’s the difference of this parallelism to a non-deterministic Turing machine?

well, about information storage, the 2 power to 300 (why the hell the number is not also power of 2?), its simply say 40 bytes, so why the hell somebody wants to "enwow" somebody by explaining this and this shitty way? I understand its about some crazy paralel computations and very specific use cases, but as he perfectly described, even encoding such info into field of qubits is far far far far more complex, not to mention almost quantum-physically impossible decoding it – and nobody was talking about some basic functional parallel ""ALU"" (arithmetic-logical-unit) yet, so I am sure almost nobody knows how to use it all to do anything usefull now and I am almost (un)certainly sure that nobody will know how to do it during next few decades still )), .. yet, unsure

That professor looks like a surfer from the 90s.

I’m still trying to understand my 1964 6 transistor radio and where are the tubes located in my new TV ?

So a quantum computer is basically a analog computer?

Bought here by google

I got los in 0 and 1

The guy is amasing.

Thank you for Sharing this information; I have a better understanding in how these work and assurance that Skynet isnt taking over the world anytime soon!

the hardest part to understand is the both states at the same time, it makes us confuse but it's just the way it is, it's a property of quantum particles, it doesn't follow our physics rules

I’d like to find out how they actually program a quantum state computer, actually at a guess it would be beyond me to appreciate.

I get to this stage each quantum bit (q-bit) has a capacity of being both 1 and 0 but as a probability of being both 1 and 0 at the same time. I could be wrong and sadly I’m probably will be but if one actually measures the actual position of a q-bit it should collapse like in a wave function of a split screen collapses when a photon is measured if it is going this way or that way. However before measuring the photons path the photon was “happy” going through both slits.

Then they talk about having a series of q-bits which then increases the computational power by having these suppositions nested as each q-bit being so much of this and so much of that at the same time. My brain hurts……..like I got me a pair of gloves but I’ve put them on back to front only to find my little pinky don’t work like my thumb. Noooooooooo! I don’t care how safe it is I ain’t gonna drink any milk until I know wether I’m dead or alive or both or should I say a probability of being both dead and alive.

Drink it Freddy it’s good for you! Gulp!