Why Quantum Computing Could Transform Our World

[Music]

this is liquid nitrogen

this is a superconductor

and this is a track of magnets

when i dip this superconductor

into the liquid nitrogen and then place

it on top of this magnetic track

something special happens

it levitates

imagine what you could do with this

technology

some people have used it to create a

hovering skateboard or how about a

hovering train getting you to your

destination faster and using less energy

or maybe a hovering car

there are many potential applications of

this technology from storing energy to

power cables

but the problem is it’s difficult to

implement in real life

why well one of the reasons is because

we need to cool down the superconductor

to minus

181 degrees celsius

but imagine if we could create a

superconductor that doesn’t need to be

cooled down that could work at room

temperature and room pressure this might

be possible

if we could understand how the atoms in

this superconductor behave

the problem is that the world’s best

computer does not have the power to

understand this

a quantum computer could change that a

quantum computer is a fundamentally new

type of computer that uses quantum

physics

everything in this world is made up of

atoms and quantum physics describes how

those atoms behave

therefore we could potentially

understand how the atoms in the

superconductor behave and that could

give us insight into creating a

superconductor that could work at room

temperatures and pressures

therefore quantum computing could unlock

the amazing applications of this

superconductor technology

the first time that i saw this

superconductor experiment was in 2009

when i was 13 years old my school got

invited to a technology event at the

local microsoft offices in reading in

the uk

i remember walking into a room and there

were all sorts of crazy experiments on

display

this is a picture from the actual event

there were explosions liquid nitrogen

superconductors it was incredible

and i remember the speaker chris bishop

the one in the green shirt

describing quantum physics and i vividly

remember his description and it seemed

out of this world but it describes how

the world works

that was the spark that led me to study

physics and computer science at

university

where i started the harvard college and

stanford quantum computing associations

now i’m doing my phd in physics at the

university of oxford specializing in

quantum computing

over the years from the time that this

picture is taken till now i’ve seen the

amazing evolution of quantum computing

and that’s why i believe that quantum

computing could transform our world

it’s because of the potential of quantum

computing that we have discovered

it’s because of the power of quantum

computing that we have uncovered

it’s because of the progress of

significant achievements that we have

ushered

let’s understand how these three

elements could lead to quantum computing

transforming our world

first what could we do with a quantum

computer that we can’t do with a normal

computer

to illustrate such an example

i have this bag inside i’m going to put

four balls

three of them are white

one

two

three

and one of them

is blue

then i’m going to close it shake it up

shake it up so that it’s random

and then let’s say i’m searching for the

blue ball

well

i could open it up

pick out a ball

and check whether it’s blue

and then i will continue

until i find the blue ball

this is how your normal computer solves

such a problem

if we had four balls it would take a

maximum of four tries since you might

get the blue ball on your last try

but what if this were a quantum computer

even if i put all four balls inside this

bag

with a quantum computer you could get

the blue ball on the first try

every

single

time

so a quantum computer could speed up

this process from four tries to one try

and in general quantum computing can

speed up searching when there is no

structure this example is called

grover’s search

and there are other processes that

quantum computing can speed up and when

i mean speed up i really mean speed up

for example there are certain processes

that could take billions of years to

solve on our normal computers because

you have to search through so many

possibilities

a quantum computer could do this in just

seconds

and this is why it’s so exciting things

that are practically impossible to solve

today could be made possible with a

quantum computer

and this could transform industries

for example in medicine you want to find

a new medicine

and that process can take some time as

you have to search through a lot of

different possibilities a quantum

computer could speed this up allowing us

to find new medicines that could cure

some diseases

or how about a vaccine we’re all

familiar with the time frame it takes to

develop a vaccine

while a quantum computer could

potentially help us find a vaccine

faster

or what about in material science you

want to create new materials that could

make the phone and the laptop you use

lighter and stronger while a quantum

computer could do this

and how about artificial intelligence

we’ve made more progress in ai now

because of the more powerful computers

we have today compared to many years ago

in a similar way a quantum computer

could advance artificial intelligence

as you can see there’s so many

applications of quantum computing from

finance to space to logistics

we could solve today’s unsolved problems

with quantum computing

which could transform our world

so how are we able to do all of this

well this is because of the power of

quantum computing that we have uncovered

now in order to understand

this power we have to understand a

little bit about how our normal

computers work let’s say you’re typing

up an email to your friend hey smiley

face what is your computer doing when

you do that well you may speak english

but your computer speaks the language of

binary the english alphabet is a to z

but the binary alphabet is just 0 and 1.

so anything you type is translated to a

sequence of zeros and ones

for example this h is translated to

these sequence of zeros and ones

and you can do this for e y smiley face

and your computer does this for

everything that you do on it it always

translates it to zeros and ones

now to illustrate this which is called

the bit i have this donut

let’s say the plane side is equivalent

to zero and the frosted side is

equivalent to one

this is called the classical bit it’s

called a classical bit because it’s used

on our classical computers and a

classical computer is basically your

normal computer

now what about a quantum computer a

quantum computer also has sort of bits

but

they’re different

we call them

creatively quantum bits also known as

qubits

and a qubit can be zero and it can be

one but it has access to something

special

it has access to quantum physics which

means it can behave in a quantum way

for example it can be a combination of

zero and one i think of it like this

spinning donut

now

it’s a combination

and this is called superposition

how powerful is superposition

let’s say you have 300 cubits in

superposition

how many classical bits would you need

to represent this

this number

that’s 10 to the power of 90.

this number is so large it’s more than

the number of

atoms in the observable universe

so as you can see superposition and

other quantum effects

make our quantum computers powerful so

how do we put our qubit into

superposition

we use something called quantum gates

quantum gates change how our qubit

behaves

for example we have this hadamard gate

so this hadamard gate takes our bit as

zero

we put it through the gate and now it

ends up in superposition

remember i showed this example with the

four balls and how you could find the

blue ball in one try well the reason the

quantum computer could do this is

because you put all of the balls in

superposition and the way you do that is

through the hadamard gate let’s say

you’re baking a cake you might use a

recipe the recipe tells you instructions

on how to use the tools you have

to change the ingredients so that you

end up getting your cake

well a quantum algorithm is a set of

instructions that we give to a quantum

computer

so the quantum algorithm is like the

recipe

the tools that we’re using

are like the quantum gates and the

qubits are like the ingredients

so a quantum algorithm tells you how to

apply

the quantum gates so that you change the

qubits so that you get your desired

solution

so how much progress have we made in

quantum computing

i’ve talked about all of the amazing

applications in the power but how much

progress have we actually made

well there have been significant

achievements that we have ushered

computers used to be only accessible to

scientists but there was a big shift in

the 1970s

and that’s when computers became

available for everyone to use in their

own home

now these computers were limited and

you couldn’t do many things with them

because they were not so powerful but

people played around with them

and as they did that transformed the

industry

well people think that quantum computers

do not exist or that they’re only

accessible by scientists

no

that shift has occurred

in 2016 quantum computers became

available for everyone to use and you

don’t even need to buy one you can just

use it for free through the internet

now these quantum computers are limited

there are a limited number of things you

can do with them they’re not very

powerful but as people play around with

them that could help the field progress

so let’s take a sneak peek at how you

use a quantum computer you can use the

ibm quantum experience when you go to

this platform you see that there are

these different lines these correspond

to each

qubit

and now you can also see the quantum

gates so these are the different tools

that we can apply to the qubits to get

our desired solution

so for example if i want to put my qubit

into superposition i can drag this

hadamard gate onto the first line which

corresponds to the first qubit and then

i can click run

and it can run on a real quantum

computer

now this is a simple example but there

are more complicated things you can do

with a quantum computer

for example you could play quantum chess

you could do machine learning you can

find the optimal path for a bus and one

of the reasons this is possible is

because of the progress that we’ve made

in the hardware now in order to

understand the progress in the hardware

i’m going to visit the leak lab at the

university of oxford they’re building

quantum computers for commercial quantum

computing by their spin-out company

oxford quantum circuits and they were

kind to let me take a look at their lab

this

is the leak lab now you might be able to

hear some of the background noise this

is the noise of the fridges cooling down

the quantum computers at the beginning

of this talk i showed the superconductor

that needed to be dipped in liquid

nitrogen so that it was cooled down so

it could work well it’s similar here

because here they’re using

superconductors for their quantum

computers so they need to cool them down

in order for them to work

in my hand i’m holding four real qubits

made out of superconductors

you can even see the cubits with your

naked eye and if you look close enough

this one actually has the shape of a

donut but not all cubits are made like

this so they do not all look like this

so these qubits are placed at the bottom

of this fridge

when i run something on the ibm quantum

experience or use any quantum computer

the instructions i send the quantum

gates are sent to the quantum computer

similar to this one

through the internet and then the

instructions are sent all the way down

to this fridge

they apply the gates to the qubits

and then we get the result back to us

incredible

and we’ve made so much progress in the

hardware about five years ago we only

had five qubits but now we have around

53 qubits and more and 53 qubits allowed

us to achieve a significant milestone in

the field in 2019

this was the first time that an actual

quantum computer could outperform the

world’s best supercomputer

google constructed a problem and then

they ran it on their quantum device

and it took about 200 seconds

then they estimated how long would this

take on the world’s best supercomputer

10 000 years

amazing

but the thing is that this is for a

problem that is constructed so it

doesn’t have real world applications yet

so the next milestone is to do this

experiment outperform a normal computer

for real-world application

and this is called quantum advantage

quantum advantage could transform this

world

and you could be a part of it

if you’re in industry you could work

with quantum computing companies to find

potential applications in your industry

if you’re interested in the power and

how quantum computing works you can

actually run your algorithms on

applications on real quantum computers

and if you’re in the quantum computing

industry you can educate the future

workforce of people that will contribute

to the progress of this field

as people unlock new applications play

with quantum computers and build a

quantum ecosystem

quantum computing becomes more likely to

live up to its potential

and beyond then it is only a matter of

time until it turns our world upside

down

thank you