<i>36C3 preroll music</i>

Herald: Welcome to the world of quantum
computing. Well, most of you is gonna just

gonna say, ah, that stuff is just for
cracking RSA keys. But there is actually a

little bit more to that. It's interesting
stuff. And our next speaker, Yann Allain

is going to introduce this world of
quantum computing to us. And he's gonna

show us a couple of application scenarios
and how to build your or our own quantum

computer. Yann.

<i>Applause</i>

Yann: Salut, hello everybody, Guten Tag,
alle - this is the only word I know in

Deutsch. We will begin this session by try
to convince you that building a quantum

computer at home is still possible. This
is the agenda. We are in a INFOSEC

security conference. Why bother with
quantum computing when we work at

cybersecurity? We will try to explain to
you in a simply manner how to our quantum

computer works. We will explain to you,
how we build our own quantum computer. And

of course, because we are CCC, we need to
know how to hack into a quantum computer.

So, let me introduce myself a little bit.
So, I'm Yann Allain, I am French. I'm used

to share my project with some security
conferences: Hack In the Box, Blackhat.

I was a speaker and trainer in this type 
of conference. It's the first time for me in

CCC, so it's very cool. I'm mostly an
entrepreneur, an engineer. And of course,

my new company, NextGenQ, which stands for
Next Generation of Quantum Computer is a

quantum company. I work in the INFOSEC
security since 25 years now. So I'm a

veteran of these domain. I fight again "I
love you" very seasoned slammer worm. If

you remember those worm and my past
activities are related to software and

hardware security. So why bother with
quantum computing when we work in

cybersecurity? If you want to make some
difficult calculation on areas like sci., for

example, to factor... a large number on a
classical computer, it will take 10 to the

power of 34 steps. It's a big number and
it will take on a normal computer 300

trillion of years. It's a long, long time.
It's why we say that RSA is secure. On a

quantum computer we have a specific
algorithm called Shor algorithm. It take

only 10 to the power of 7 steps. It's a
smaller number and it takes only 10

seconds. However, you could think that the
statement is a little bit overhyped. Yes

and no. No, because Shor algorithm is able
to break RSA. This is the goal of this

algorithm in the human time. However, at
the moment we speak - to break a big

number with this algorithm you need to
have a much bigger quantum computer that

exists nowadays. For example, you need 4
thousands ideal qubits quantum computer.

It doesn't exist for the moment. However,
quantum computing could be used also for

some benefits for our domain of INFOSEC
cybersecurity. There is many advantage on

the corner. You can use a quantum computer
or quantum technology to generate true

random number. This is useful for
cryptography. You can deploy what is

called blind quantum computing. In fact,
blind quantum computing is the ultimate

privacy for the cloud, for example. Some
guys try to launch, what they call a

Quantum Internet. It's not so easy as
cable networks and with a particular

future for us, that could be cool to use
if you use a Quantum Internet. Everyone

that tried to spy you on the line will be
detected. So it could be very useful. And

of course, quantum computing brings to 
the massive new power of processing.

But, how those computer works? This is the
1 slide quantum mechanic course. Why does

a fancy new quantum computer are so
powerful? In classical computing, we use

bits. A bit is only in two states, 1 or 0.
In quantum computing we replace the bits

by the quantum bits, which we call then
qubits. These qubits follow the quantum

mechanical principle called superposition.
And this principle is able to do, to

provide to the user several step at
the same time. So if you use a qubit, the

qubit could be in the state of 0 and 1
nearly at the same time. It's not exactly

what it is, but for us as a computer
scientist, we could understand that it's a

zero and 1 at the same time. And of
course, if a quantum computer. This is a

quantum computer wants to manage to deal
with all this qubits. It deals with all

the solution of the quantum register at
the same time. So it will speed up the

process of data computing because you take
all the space generated by these quantum

register and in one clock time 
the computer process all

solution. This is mainly why and how the
quantum computing is so powerful. So it's

cool. So I want to build my own qubits. So
this is my journey to build my own quantum

computer. And you will see that there
is some success and failure in most of the

time. And I'm in the middle of this. So,
I need to choose a technology to build

my own qubit's hardware. This talk is mainly
about hardwear. How to build your own

hardrwear, to build your own quantum
computer. So my ingredients, I need to

find a suport at the hardware level that
behave like quantum mechanic. Say you need

to be able to do a quantum computer. So I
need to find something that's behaving at

atomic scale. I need to be able to build
it. So I want to be able to use my do-it-

yourself skills. And I want that my
quantum computer works at room

temperature. If it could be stable
machine, it could be the best. There is

many, many technology to build you on
qubits. This one called superconducting

qubits is used by a small startup like
IBM, Google. Mainly the big one use this

technology. Microsoft tried to use this
technology. This technology with Diamond

vacancy is used by university in Australia
and in Ireland, I think. And of course, I

use this technology. I use the technology
called trap ions. So I trapped ions to

make a quantum computer. So my low level
hardware support and device to do some

calculation with my quantum computer is
atom. Why I choose an atom to make some

fancy new qantum computer? The main
reason is because I think I may be able to

build it in my garage. It's enough
affordable and well spread technology

because we use technology that has been
developed in 1945. There is a lot of

experience with this type of technology.
And the main reason, in fact, the qubit

quality is better than any other technology. 
We have a long coherence time.

If you have a long quantum coherence time,
you can make much larger program, for

example. So we need to share a bit of
theory to understand how this type of

computer works or I have a choice. I made
a choice. I could have take time to make

dozens of equations mainly I don't
understand those equation to explain to

you how to make some calculation with
ions. But I found a video on YouTube and I

would like to share you this two minutes
only video to let you understand how at a

theoretical point of view a quantum
computer based on ion trap works. Let's

see if it works.

<i>background music starts</i>

Video: .. electrically charged atoms make
for excellent qubits. This kind of

research has paved the way for a quantum
computer prototype. Like an ordinary bit,

a qubit can be a 1 or a 0. A Qubit differs
from a bit because it can also be in

combinations of these two states. An ion
qubit is made from two of its energy

levels. Ions of the same type are
identical. So adding more qubits is

simple. You just need to add more ions to
the system. This is a major plus because a

quantum computer will need lots and lots
of qubits. Qubits must be configured in

certain quantum states in order to perform
quantum tasks. In an iron trap, taylored

Laser pulses can change the energy of an
eye on setting it into quantum state 1, 0

or a combination of the two. The qubit
surrounding environment sometimes sneakes

in and destroys the qubit state, a covert
act that can ruin a computation. But some

ion energy levels are naturally isolated
and scientists have come up with clever

ways of adding an extra layers of
protection. Quantum computer calculations

are made from steps called Logic Gates.
This will often involve more than one

qubit, which means the qubits should be
connected in some way in an iron trap.

Neighboring ion qubits are connected
through their collective motion. This

happens because of their electrical
repulsion. Laser pulses target the motion,

enabling gates between any pair of qubits.
To get the result of a calculation,

scientists need to tell whether a qubit is
in state 1 or 0. Shining laser pulses onto

the ions makes only one of the two qubit
levels flouress. So the result, light or

no light, gives information about the
calculation. Because many qubits are

needed, quantum devices must be designed
to be scalable. Researchers can only cram

so many ions next to each other in a
single ion trap before they get too

unruly. But with modules each containing
tens or hundreds of ions, they can start

to wire up a large scale quantum computer.
Flight from individual ion modules can be

collected, allowing ion qubits from
separate modules to communicate using

photons rather than their motion. So far,
scientists wired up two such modules and

they are getting ready to deploy larger
devices using several more.

<i>background music stops</i>

Yann: So now, congratulation, you are
experts in ion trap quantum computing. A

two minute video only is necessary.
However, we like to build this quantum

computer. So the plan is the following. We
need some ions. You know that now. You

need an ion trap. You need a vacuum
chamber because we need to isolate our

atom from the environment to maintain the
quantum states. We need some laser, as you

show in the video, to manipulate the
quantum states. We need some low level

software, to timely send the pulse of
laser to manipulate the ions. And we

need a camera to measure the ions quantum
states. It's easy, no? So let's go to the

difficult parts, I think mainly I would
like to say that it's a work in progress.

It's good, well, to say that it doesn't
finished. And, just an alert, we need to

manipulate, very high power electric voltages.
So if you want to do this at home, do it

at your own risk. It's not my fault. So
how to create? First, we need to create an

ion trap. How to create an ion trap and
what is an iron trap? An iron trap is

mainly a bunch of electrode with specific
3D or 2D geometry. We send to the

electrode medium to high power voltage. AC
voltage, alternative voltage. From 200 V

to 6 kV. It's a big number for a voltage.
We will use moderate to high frequency.

This is due to the trap theory. Someone
have won the Nobel Prize to explain that

to trap an atom, you need to use an
alternating voltage. And this electric

voltage will make an electric field, and
the goal of the electric field with the

trap is just to maintain all the atom in a
chain that will float over the air, over

the trap. So how to achieve that at a
small, small company budget, we say,

because it's not for our best, I think.
Let's go. So I use my ultra high tech

military grade garage. I use 3D printer,
local CNC machine, PCB milling techniques,

only open source software. KiCad, FreeCAD,
FlatCAM. KiCad for the electronics,

FreeCAD for the mechanics and FlatCAM for
the CNC. I used some high voltage

transformer, classical electronics and of
course isolated gloves. Security first.

Safety first, sometime. And of course, I
use eBay as a main procurement utility.

First try. I need to make a classical
Paul trap, of course, when I

don't know, how it works, I go to Google
and I find that some institution like CERN

have a project to make an ion trap from
3D printed parts. I use conductive ink and

only high voltage power supply. So I need
to build this. There is the high voltage...

air, two electrodes and one ring
electrodes. The goal is to trap ions with

that. So this is the main laboratory I
use. So you have a variac. We take the

electric plug from your domestic electric
network. The high transformer and air. So

the 3D printed, you have two electrode and
the camera. This is the electrode. It's a

very safe wiring system. For safety
reason, I put some resistance here just to

limit the currents. The first time.

<i>laughter</i>

Yann: In a more closer way you will see
that the high voltages is coming from

this. We will apply the voltages to the
electrode. And the camera is here. Just

see what the electrode will do. It works.
I'm succeeding trapping some macro

particles. This is not ion for demonstrational 
purposes, but we succeed to

trap in the electrode some particles.
Macro particles. But we have a first

failure because with this geometry, we
couldn't shine correctly the laser to

manipulate the quantum state. First
failure. Second try. We need to to make,

another ion trap based on a new topology
or new geometry of electrode. And this

time we use a linear port to facilitate
the laser shining. So again, I need to

design on my own this new type because 
the CERN don't provide me the 3D

printed parts. I use conductive ink and
high voltages. So the goal is to design

this. And in this trap you will see
that we will trap the ion in the chain in

the middle of the trap. So I use my 3D
printer. I make some rods. The supports.

Some electrodes. I built all the system
and I plug the cable, the wiring and the

trap. The particle will be trapped in
these regions. For this second trap I

didn't use a resistance to limit the
currents, so it's impossible to touch this

electrode because of death.

<i>laughter</i>

Yann: And it works, again.

<i>applause</i>

Yann: And in fact, this is a chain of
particles that nearly clearly aligned. And

this is my first quantum register of eight
particles. But, this is the biggest

failure, I need to put this ion trap in
the vacuum chamber. A vacuum chamber is

this type of thing. It's a big bunch of
metal and we put the iron trap inside

this. However, first, why we need a vacuum
chamber? To be able to isolate particle

from the other atoms in atmosphere to
avoid collision between atoms. Because if

we have collision between atoms, the
quantum state is destroyed and the quantum

processing is destroyed also. So we need a
vacuum chamber. That's for them. 3D

printing parts are not compatible with
Ultra High Vacuum (UHV) environments. So

it's a big fail? Are we doomed? Maker is
our job, really. So we need to find a new

solution. We have found one. So I need to
find some materials that are compatible

with UHV environments to build an ion
trap. I ask the NASA, because NASA sends

electronics in space. Space is like a big
vacuum chamber. So they have a list of

materials publicly available to be able to
use some material that are compatible with

a space condition. They are professionals.
So what are the candidates, the material

candidates for my ion trap? I need to use
some gold for electronic conductor. I need

to use ceramic for mechanical supports and
Kapton cable for wiring inside the vacuum

chamber. So maker is really, really our
job, because I need to find an idea to

transform my 3D printed linear ion trap to
somthing that is compatible with UHV

environments. So I need to read the
manual. There is a lot of literature on

quantum computers on Google, on Internet.
So I have a bunch of books about quantum

mechanics and research paper are
full of details. I found this: some guys

in 62 transform a linear Paul trap
with rods to a planar ion trap with planar

or surface electrodes. That's cool. So I
need to transform this. To that. Oh, boy.

I need to make my own chip. Price for
complete chip factories are around 200 M$.

I called Intel, they don't want to sell me
one. And it's a bit out of my budget

scope. A bit. Let's think this five
minutes through to find a solution. In

fact, it took me two months to find an
affordable solution to do that. So I

wanted to make a new design like a boss,
of ion trap. I use a CNC, a 300$ CNC, come

from Amazon. And then I found an empty
ceramic chip carrier on eBay from a

Norwegian guy. And I designed a simple
KiCad PCB. So I use this. This is the

ceramic chip supports. And what you
see in yellow - it's gold. I designed in

KiCad this PCB and this time we apply
electric field, high voltage electric

field to this electrode, this one and
those one, and it creates an electric

field to align all the macro particles of
the ion in this line. And this is

how I made my quantum computer chip.

<i>applause</i>

Yann: Thank you. And the better 
is that it works.

<i>applause</i>

So, tada, I have my first quantum

computer done on my garage and just 
keep calm and except I'm a boss.

<i>laughter</i>

Yann: And it is not just a slide. Well,
because if you want to see one of my

prototype, I bring it so you can touch it
and see how it works. But when you design

such complex things; I am not a physicist,
I'm just an engineer. A crazy one. But how

to be sure that I am on the right road. I
went to the Science Museum in London few

few months ago, and there's this
exhibition from our friend of GCHQ. Do you

know what GCHQ is? It's like doing stuff
of the UK and they made an exhibition

about cryptography. And in this museum,
they present a quantum computer based on

ion trap technology. Thanks. This is the
experimental part they show in this museum

about quantum computer. In the right
corner of this exhibition there is a

wafer. On the wafer you have the electric
design that they done to make their own

iron trap. This is the design of the GCHQ.
This is mine. I think I'm on the right road.

<i>applause</i>

Yann: Of course, I need to build my own
vacuum chamber, it's not the difficult

part, the vacuum chamber. It's just metal,
you need not... you need some nuts, bolts,

thin metal and pumps. A lot of pumps to
suck out all the air in the vacuum. So I

bought off eBay a different type of pumps.
I like my vacuum chamber. This one, pretty

one. And I put the ion trap inside the
vacuum chamber. And for now I'm working on

the laser, an optical setup. And this is
the main difficult part for this quantum

computer because with fancy, new, numerous
wavelength for laser and we need to have a

very precise wavelength to be able to
manage all the atom, the energy level of

the atom to make some calculation. So, of
course, I could have and I have asked some

professional of these devices to send me
some proposal. A laser costs around 25 k€.

A rule at least for this type of
instrumentation. Or you can do it yourself

from 2 k€. So I decide to make my own
laser setup. I'm not a laser, optical or

laser specialist. The first time I play
with laser. And there is everything on

the web. You can learn everything with the
web. And I found this type of schematic

you'd use either laser diode, some fancy
optical lense. grating mirror that lets

you choose... mainly choose what the
reference frequency you want to use.

There is a sort of loop control with PID
control, which is for an electrician like

me normal things to do. I don't know why
all those fancy commercial product cost a

lot. I don't know yet. Perhaps I will have
some failure in the future, but I don't

know. So I ask a guy on the Internet
that's sold me a laser in kits. You can

buy and mount you own laser. And this
laser is controlled by an arduino. So you

have fancy mirror. The HeNe aluminum laser
tube and you can make your own laser at

home also.
I need a bunch of optical mounts and

supports to support the lens and mirror,
etc.. And as I bought a 3D printer for my

iron trap that I can not use anymore
because I use a vacuum chamber. I use the

3D printer to make all the optical mounts,
in fact. So it saved me my money again.

However, you need to know that it's still
a long road to have a complete quantum

computer because I need to set up all
these fancy optical and laser. This is my

job at the moment. Mearly I have 6
months to one year of works. But the good

news is that at the software level,
everything exists. If you need to have a

quantum compiler to make your code, it
exist. At the moment, it's open source. If

you need to have some firmware to
make some pulse and laser control, it

exists. And it is open source. So I am
trying to convince you. Let me know if you

agree with me, that doing a quantum
computer at home - it's doable. You agree?

<i>applause</i>

Yann: But we are at the CCC. How to hack
into a quantum computer. This is

different part. It's easy. Just do what we
do when we are infosec guy. Do the same

things we do as usual: Hack the weakest
link. You must know that when you build

the quantum computer, there is few things
that behave in the quantum mechanical

regime. You just only need this chip, for
example, and some laser. But all the

equipment surrounding the quantum
parts of the quantum computer is classical

system. This is wave generator. Classical
computer. Some IoTs, some programmable

industrial systems. Sometimes they have IP
address. If they have IP address, they are

vulnerable. So, the main I have to
know to hack into a quantum computer is to

act the surrounding classical embedded
system. So. Small company that is a

competitor of me. It's cool. It's a
startup called IBM. They used

superconducting technology to build their
own quantum computer. Their processor is

just behind this delusion of refrigerator
because they need to cool down their

processor to be able to use the
superconducting capability. Mine work at

room temperature. And surrounded this
processor, the researcher explained, this

is a very good video to understand how 
it works. And surrounded this quantum

part of their quantum computer you have a
bunch of instruments. And if you zoom in,

you see. If you zoom in this wave
generator, it's a wave generator to send

pulse to the superconducting processor.
There is a sticker. And this sticker, in fact..

<i>laughter</i>

Yann: So, of course, for security reason,
I make some X to not show the complete

passwords. So as a conclusion. I'm trying
to convince you that quantum computing and

quantum computer hardware is doable at
home. So far cybersecurity or so-called

cybersecurity specialist, you need to
make, to adapt your own risk analysis.

Because it's doable at home. Just
understand that - is doable at home. They

will, all these quantum computer will be
used for good, bad and ugly. Just

remember, GCHQ has a prototype in the
museum. It would have fun if I could have

seen the production quantum computer of
the GCHQ. Of course quantum computers are

hackable as any normal computer. So it's a
good news for the cybersecurity industry.

But you need as a community of maker in
CCC, we need to be prepared to learn and

how to use them, how to ask them how to
program them and at the software level,

just, you need to unlock your classical
brain, the classical software brain

because if I want to mention something at
the software level, if you want to do some

control codes, you need to be able to use
your code without any variables. You can't

use variables in quantum codes because if
you use variable, you make a copy of a

quantum state. Making a copy of a quantum
state is impossible. So you can't use them

to make a vairables or use variables in
a new program and you can't debug it

because if you debug it, you make a
measurement. If you make a measurement,

you destroy the quantum states. So be
prepared to allow your brain to be able

to make some code in the quantum world.
But it's fun. Some time. Thanks for your

attention. And if you have any question,
it will be a pleasure. And as I'm French,

I need to have a two hour lunchtime.

Herald: Fantastic. Merci beaucoup.
We have a lot of time now for your

questions, answers. Line up at the
microphones, please. And let's have a look

if there is something from the Internet.
Yes, there is. So please. First one from

the Internet.
Yann: Where is the Internet?

Signal-Angel: All right. The Internet's
quite impressed by your talk. So that's

just a statement. Like everyone's very
happy and pleased with your talk.

Yann: Thanks to the Internet.
<i>light laughter</i>

Signal-Angel: All right. You have a few
questions. So the first one is what

properties should the element be chosen
for the ion trap?

Yann: What? Sorry.
Signal-Angel: So what are the properties

that should be looked at for choosing the
element for the iron trap?

Yann: What atom? I think the person asked
what atom I used. I used the atom from

calcium because those atoms have a
specific.. because there is a lot of

literature available. So it's easy for me
to understand how it works. Researchers have

done all the work before. And I used the
atom because there are some energy level

in this atom that is better protected 
from the environment.

Herald: OK, let's quickly switch to
microphone number 3.

Mic3: Thank you for it. Thank you
for your talk. My question is, what's the

catch? If your design already exists in
prototypes out there and it seems so much

easier than working with superconductors,
then why isn't everyone already doing

this?
Yann: Why someone choose superconducting

and not ion trap technologies? Is that
your question?

Mic3: Correct.
Yann: I don't know.

<i>light laughter</i>
Yann: Every time there is this type of

question, why the big one used
superconducting technology and why are you

using iron trap technology? Mainly the
answer could be that the big one is from

the microelectronics domain. So a
superconducting qubit is done on a

wafer. So it's usual for this type of
company to be able to build these

type of qubits. I think it produced a
habit.

Mic3: Okay, thank you.
Herald: Okay. Microphone number two,

please.
Mic2: I'm very impressed. But.

Okay. You mentioned that hobbyists can't
really afford this. A small company can.

So just as a ballpark figure, I would like
to ask the question. Nice. How much?

Yann: All I've shown you here. It cost
only less than 15 k€ of material for the

moment. It is not for a hobbyist - 
for small company.

Herald: Okay, one question from the
Internet. Signal-Angel, please.

Signal-Angel: All right. The next question
is: is your next step going to be singling

out individual ions?
Yann: Sorry, can you repeat?

Signal-Angel: Would your next step be
singling out individual ions for the next

step in your quantum computer?
Yann: We try to manipulate single ions,

but in fact, it's the goal with laser.
With laser you shine a laser of individual

qubits. And with another laser, you make a
link between the ions with the common mode

motion of the ion chain and you change the
state of an individual ions, you transfer

the state of these individual ions to the
chain, which move because ions are

electrically charged. So they repell each
other and this act as a bus and you

transfer the quantum state information to
to a second ion to make a logic. So the

goal effectively is to be able to
manipulate one ions. We shine a laser on

the individual atoms. This is the goal.
Herald: Okay. Microphone number four,

please.
Mic4: Google announced recently that they

achieved the quantum supremacy. What is
your opinion on this theme?

Yann: They have done a very good job
for that. I think they show to the world

for the first time that a quantum 
computer is able to do a calculation that a

classical computer will never be able to
do in the classical world. However, is

that calculation useful? I'm not sure,
except for one thing, it's able to

certify the randomness of a number and it
could be useful for the cyber security

world. So it's I think and for my company,
I have no money to spend to marketing

thanks to Google because they show the
world the power of quantum computer. So

it's cool for me.
Herald: Okay. Microphone number two,

please.
Mic2: Hello. Thanks for the nice talk.

I'm a material scientist from Offline
Gießen. Maybe you heard about our incident

here. I was asking what are your current
problems with this? For example, I mean, I

think I have too many questions to ask
here now. But for example, we saw that you

had some like little pellets that were
floating over your structure. But these

are not the atoms that you are trying to
to confine with each other so you can make

calculations. So you didn't say anything
about how you are trying to achieve this?

And what is your current state? I mean,
have you- could you start some crude

calculations on this already or... ?
Yann: Not for the moment because I need

to shine the laser in the right direction.
So for the moment, I am building the

optical setup.
Mic4: Okay. All right. Maybe there are

some possibilities how I could help you
with your project.

Yann: You're welcome.
Mic4: I have an access. If I could ask the

right people, I'm not in a position to
promise something to you now. But for

example, we have an nano scribe laser
system with this like a 3D printer. But

you can build things on nano levels, on 
nano meter scale.

Yann: What is the cost of using that?
Mic4: The cost of the printer is around

300.000€.
Yann: Oh... I take it.

Mic4: All right.
Yann: Thanks. Thanks. Thanks for your

help.
Mic4: Maybe after the talk we can get in

contact.
Yann: Oh yes, we have a dinner. <i>laughter</i>

Mic4: All right.
Herald: Two new friends, actually.

<i>applause</i>
Question from the Internet, please.

Signal Angel: All right. So how many qubits 
is it possible to make in the garage?

Yann: For the prototype, we think we
are able to do some 10 to 15 qubits with

one ion trap. The goal is to chain the ion
trap. So we have many, not as many as we

want, but we could raise the number of
qubits to 100 qubits.

Heral: Okay. Microphone number three,
please.

Mic3: Which calculations do you plan to
perform on your quantum computer?

Yann: I don't care. I build thing and
software guy do their code. It's not my

job.
Herald: Okay. Microphone number four, please.

There is somebody.
Mic4: Hello. So your optical setup

reminded me of atomic force microscopes.
Are you aware of what they are?

Yann: Perhaps.
Mic4: They are essentially an optical

setup with a micro scale tip at the edge
that rasters, that scans across the

surface and can detect nanoscale features.
But the cool thing is that even though

this is a scientific instrument, there is
also open hardware designs for that. And

maybe you can see the ideas from that for
your optical setup, because once again

you've got precise lasers, at least on the
geometrical side. They have to be

precisely alined and everything.
Yann: Thanks. Thanks for the information.

And of course, we use a lot of
spectrography techniques in this type of

computer.
Heral: Okay, we have somebody over there

at microphone number three.
Mic4: Did you consider optical quantum

computers with entangled photons 
and such stuff?

Yann: I did- This was my first choice in
fact. However as far as I know, I'm not a

physicist, it's difficult to make some and
trick entanglements and, not

entanglement... It's difficult to make
some photon to talk to each other. Let's

say that. So it's a complicated way to do
something with multiple qubits. But

photonic is a good technology because it
works also at room temperature. But I

prefer to have a vacuum chamber in my
garage.

Herald: Okay, let's interrogate the
Internet again.

Signal Angel: So you've mentioned that you
should not be doing measurements on the

quantum computer. So have you tried doing
any measurements on your prototype?

Yann: Measurement of what?
Herald: This is hard. I think the Internet

cannot really reply now. So can we...
Yann: Internet is limited. I think we can

give the guy that ask the question. He
wants to send me the question I can answer

just after all.
Signal angel: But I think they are talking

about electric field.
Yann: Ah, no. I just I don't make any

measurement. I'm an engineer. And as I am
a good engineer, I just plug things. And

just see what happens. I have no idea of
the electric field generated. No idea.

Again.
Herald: OK. Microphone number two, please.

Mic2: Hello. Thank you for the talk. So
after you generate the vacuum in your

vacuum chamber, how do you actually
introduce the right number of ions and how

do you keep them in the place where you
need to have them?

Yann: It's a good question. In fact, we
don't introduce the ions. We put a calcium

stone, sort of calcium stone, in a sort of
oven, it's just a tube. We send current in

this tube, the tube heats the calcium.
They make some vapor and we shine a laser

on the vapor of neutral atom of calcium.
And this creates the ions. And this ion is

trapped because it's now electric charged
by the electrostatic field we make with

the ion trap. So we just introduced before
closing all the vacuum viewport and all

the nuts and bolts. We just put a piece of
stone of calcium, neutral atom. So

everything is in the chamber before we
turn on the quantum computer or the

chamber.
Herald: OK. We stay at microphone number

two. There is another one.
Mic2: OK, second question. What you're

describing is you have a linear array of
right now macroscopic particles. You will

have a linear array of ions that are then
coupled by kind of common vibrational

modes. So they need to see each other's
electrical fields. So I am wondering what

the characteristic length scale between
macroscopic particles versus ions would be

if you want to have some meaningful
vibrational modes that don't immediately

get drowned by external thermal noise.
Yann: So if I understand correctly the

question, you ask me what is the 
dimension between the ions?

Mic2: Yes. I mean you you are pretty big
compared to the IBM guys.

Yann: Yes. I'm big. Yes. You're right. The
main dimension we use between ion it's few

micron. And if some researcher succeeds to
align 100 ions. So you have a chain of 100

ions multiplied by five to ten microns
between ions. This is the length.

Mic2: But I mean, on your substrate, 
you ou have a fraction of a

millimeter. Yeah. Between the...
Yann: It's because it's prototype.

Mic2: Okay.
Yann: You're right. I need to squeeze the

design a little bit, okay? It just need to
buy a better CNC machine.

Herald: OK, we got some question from the
Internet again.

Signal angel: All right so this one is...
This is more towards knowing about the

GCHQ exhibition. Is it still open do you
know?

Yann: Yes. I think, you have a
free ticket if you want. It's free. In

fact, it's free. 
Signal Angel: I guess people will contact

you on Twitter for that.
Yann: Yeah. I make some touristic business

or so. I can help.
Signal Angel: Everyone was impressed with

your GCHQ hack.
Herald: Ok, any more questions. How many

people are working in your garage?
Yann: There is me and sometimes one of

my daughters, which is, 10 years old.
Herald: Pro team.

Yann: Yeah, a big one.
Herald: Okay. Any more questions from

the audience, from the Internet? We have 
time. Okay, I'm gonna close that session

now, thank you very much. 
Big applause again for Yann.

<i>applause</i>

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