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