From Quantum Science to Quantum Technologies Raymond Laflamme laflamme@iqc.ca www.iqc.ca

F r o m Q u a n t u m S c i e n c e t o Q u a n t u m Te c h n o l o g i e s Raymond Laflamme

laflamme@iqc.ca

www.iqc.ca

Message

-Quantum Information Science has taught us the right language in order to be able to talk and be talked to by quantum systems (atoms, molecules etc..)

-From that knowledge we are learning of

taking advantage of the quantum world and

although quantum computers are still some

time in the future, the impact of quantum

sensors has already started to happen.

The Quantum World

“a place where there are no penalties for interference”

Miriam Diamond, USEQIP student

Undergraduate Summer Experimental Quantum Information Program https://uwaterloo.ca/institute-for-quantum-computing/programs/useqip

Cycle of Discoveries

C

Cuurriio ossiittyy

U

Unnd deerrssttaannd diinng g

C

Co onnttrro oll T

Teecchhnno ollo og gyy S

So occiiaall IIm mp paacctt

Successes of Quantum Information Science

• Discovery of the power of quantum mechanics for information processing -new language for

quantum mechanics

• Discovery of how to control quantum systems

• Proof-of-concepts experiments

Successes of Quantum Information Science

• Discovery of the power of quantum mechanics for information processing -new language for

quantum mechanics

• Discovery of how to control quantum systems

• Proof-of-concepts experiments

Plus !!

Development of practical quantum information technologies

On the first floor …

Mike and Opehlia Lazaridis Quatnum Nano Center University of Waterloo

Quantum Technologies today

Made possible because the world in quantum

Lasers LEDs

MRI Transistors

Quantum Information: The QUBIT

Quantum Dots

Spin-based QIP Superconducting Qubits

Quantum Optics

Trapped Ions

Trapped Atoms

Quantum Sensors

Harnessing the quantum world will allows us to achieve:

• ! Greatest precision

• ! Greatest sensitivity

• ! Greatest selectivity

• ! Greatest robustness

• ! Greatest efficiency

Quantum Information provides the right language and tools

NMR quantum computing

Brief history of NMR Bloch and Purcell

Applications of NMR -MRI

-molecular structure -chemical analysis

-concrete research -tire compositions - molecular dynamics -…

H

C

Cl Cl Cl

C

13

13 1

2

Trichloroethylene

=|010

>

N S

NMR quantum computing

Brief history of QIP achievements

• ! laboratory feedback on quantum control

• ! theoretical challenges: DQC1

• ! development of experimental QECorrection

• ! …

-push the quality of quantum control

Cl Cl

C₁ C₂ C₄ C₅

C₆ C₇

C₃

H H₄

H₂ H₃ H₁

H₅ O O O

S

1

2(I + αZ) I^⊗n

2ⁿ

John Waugh

Challenge with inhomogeneity

B+!B B B-!B

"#

"

> "

> "

A rf inhomogeniety selective pulse

-1 1 2 3

0.2 0.4 0.6 0.8 1

rf inhomogeneity

# of spins

3.0% 4.5% 6.0% 7.5%

0.2 0.4 1.0

0.6 0.8

1.5% rf inhomogeneity

amount of signal

x y

z

i

€i

R

(90) ! R

(180))

!

(R

(180)R

(180))

! R

(90)

0

1

X Y

Z

!!

""

Find a pulse sequence that keep the spins that are within a given homogenity bound and spread the other around the sphere

NMR Oil well logging Application to oil well logging by measuring presence of

• ! water/oil

• ! porosity of rocks

• ! motion of the liquid

MRIL® Magnetic Resonance Imaging Logging

Direct Measurements Produce Better Results

The proof is in the logs. Halliburton's Magnetic Resonance Imaging Logging (MRIL®) is revolutionizing the openhole logging business through direct measurement of reservoir fluids, such as oil, gas, and water. Now, operators can identify water-free production zones and previously hidden pay zones in their wells using MRIL technology.

Increasing reserves by providing a complete, accurate analysis of a low resistivity/low contrast interval Identifying commercial zones in a laminated, fine-grained sand and shale formation

Improving completion success in a low permeability reservoir Establishing water-free oil production in a low resistivity zone …

Small pore

Amplitude

Time, msec

Large pore

Amplitude

Time, msec

http://www.halliburton.com

Measuring a magnetic field

φ(t, τ ) = 1

 t+τ /2 t−τ /2

µB(t)dt

0

1

X Y

Z

!!

""

x

y z

x

y z

x

y z

x

y z

x

y z

x

y z

precession (t- /2,t)�

precession (t,t+ /2)�

�spin-echo �spin-echo

N S

5 10 15 20 25 30

-1 -0.5 0.5

Cos[F] 1

F

Ψ(φ(t, τ )) = |0 + e^{iφ(t,τ )}|1

P rob(|00|) = Cos[φ(t, τ )]

Technology comparison

MRFM (2004)

Atom chip (2005) MRFM (2007)

SQUIDS (2008) MRFM (2009)

1!m 10nm

10^-8 10^-6 10^-4 10^-2 10⁰

Distance [m]

Superconducting qubits as sensors

History of superconducting (qu)bits

•! long experience (> 50 year) of behavior at classical level.

•! versatile and easily tunable

•! (hopefully) relatively easily scalable

•! one of the first quantum use: test quantum mechanics

Superconducting qubits as sensors

Superconducting qubit: mesoscopic system that using superconducting material to build ``artificial atoms’’

C=capacitance L=inductance

Q=charge on the capacitance

$=flux through the loop

E = L 2

dQ dt

2

+ 1

2CQ² = 1

2LΦ² + 1 2CQ²

X or &

Potential Energy

E=hN E=hN

E=hN x /2²

E = 1

2p²+ 1

2(q − Λ)² Λ is the control parameter charge qubit Λ = Vg← gate voltage

phase qubit Λ = I ← bias current flux qubit Λ = Φext ← external flux

Superconducting qubits as sensors

Superconducting qubits: mesoscopic system that using superconducting material to build artificial atoms”

Need to make energy level different: do this by adding a Josephson junction

E = 1

2LΦ² + 1 2CQ²

-10 -5 5 10

20 40 60 80 100

+ E_j cos(2πΦ/Φ₀)

Josephson junction

a)

b)

Superconducting Qubits: A Short Review M. H. Devorety, A. Wallray, and J. M. Martinis

Superconducting Circuits for Quantum Information: An Outlook M. H. Devoret and R. J. Schoelkopf, Science 339, 1169 (2013);

Sensitivity vs resolution for our detector

Lupascu’s quantum sensor

Nature Communications, 3, 1324 (2012), preprint arXiv: 1301.0778.

DARPA compilation (QUASAR)

sensitivity of 3.3 pT Hz1/2 for a frequency of 10 MHz.

Can we do better?

NV centers

!

!

!

Energy diagram

N V

Scientific American, October 2007

NV centers

Explain how they work and the achievement of Yacoby

a

MW coil Sensor NV

Target spins Scanning diamond

platform

Excitation laser

MW

2 B

z x y

|1〉

|–1〉

ω

|0〉

γ

Yacoby, Nature Physics 9, 215, 2013

50 nanometer above target

Measure single spin

“long coherence time”

-room temperature

-can initialized the qubit

-measure electron spin resonance

Electron spins:

-> electronic resolution: 2.7 Å

Nuclear spins:

-> nuclear resolution: 6 Å

Neutron interferometry

Collaboration of IQC, NIST and Brockhouse Institute

Interesting use of neutron interferometers:

non-destructive measurement at the atomic scale: characterize magnetic, nuclear, and structural properties of materials, protein structure, can be use on biological or cold material, fundamental studies in physics, information science and solid-state physics

Quantum sensors

Dima Pushin

D. A. Pushin,M. G. Huber, M. Arif,and D. G. Cory PRL 107, 150401

Neutron interferometry

Quantum sensors

-but the interferometer is fragile -neutron characteristics

velocity about 1000m/s

wavelength is about ~0.2 nm i.e. a few angstrom

Dominant noise mode

Quantum Error Correction

Probability of success per gate: P ~(1
%)

Probability of success for n gates P

~(1
e)

:

i.e.exponential decrease Classical error correction thought to require:

• ! discrete errors (bit flips.. does not work for analog devices)

• ! copying information (but no cloning theorem)

• ! measure the bits (destroy coherence)

A simple family of code:

Decoherence free subspaces:

They are subspaces that are not affected by noise

e.g.

this state

is invariant wrt rotations

this state is not invariant

| ↑↓ − | ↓↑ | ↑↓ + | ↓↑

Neutron interferometry

an example of macroscopic quantum coherence

I

= "

= t

r

[ 1+ cos # ( ) ]

Measure the neutron Intensity.

In this case that is the number of neutrons per unit time.

I

= "

= r

[ ( t

+ r

) ^{# r}

^t

^{cos $ ( )} ]

Neutron interferometry

an example of macroscopic quantum coherence

Measure the neutron Intensity.

In this case that is the number of neutrons per unit time.

|0>

|1>

1

1 1

1 2

2 2

2 3

3

4

4

1 1 2

2 2 3 2 4 4

|0>

|1>

|00>

|01>

|10>

|11>

3

1 1

1 1

2 3 2

4 4

|0>

|1>

|01>

|10>

3

Neutron interferometry

The 4/5 blade interferometer robust again rotation

beam blocks

neutr on

beam phase flag

perfect Si single cr

ystal interferometer O-b

eam

H-beam

beam blocks neutron

detectors

(220) +

neutron beam

interferometer enclosure

motor

off-center mass

a b

c

low frequency vibration isolation table

vibration isolation pads

vibration isolation pads

650

600

550

500

450

Neutrons per 300 sec

-1.5 -1.0 -0.5 0.0 0.5 1.0 1.5

Phase flag rotation, (°) No vibration

8 Hz vibration 3 blade

700 650 600 550 500 450 400 350

Neutrons per 300 sec

-1.5 -1.0 -0.5 0.0 0.5 1.0 1.5

Phase flag rotation, (°) No vibration

8 Hz vibration

4 blade

a

b

S/N ratio increased by 600

GEO600: gravitational wave detector

Use Michaelson interferometer to precisely measure distance

GEO600: gravitatinal wave detector

Use Michaelson interferometer to precisely measure distance

vacuum

The Vacuum in Quantum Mechanics

Uncertainty relations

X or &

Potential Energy

E=hN E=hN

E=hN x /2²

X

P

∆X × ∆P ≥ /2

X

P Ground state

Squeezed Ground state

GEO600: gravitational wave detector

H. Grote,* K. Danzmann, K. L. Dooley, R. Schnabel, J. Slutsky, and H. Vahlbruch

Max-Planck-Institut fu¨r Gravitationsphysik (Albert Einstein Institut) und Leibniz Universita¨ t Hannover, Callinstraße 38, 30167 Hannover, Germany

Squeezed vacuum + 15.2MHz subcarrier field Injection locked

high-power laser system

2 sequential mode-cleaners (8m round-trip)

MPR T=0.09%

MSR T=10%

600m north arm (folded in vertical plane)

600m east arm (folded in vertical plane)

BS MCe

MFe

Faraday Isolator

OMC MCn

MFn

Data output h(t) Michelson output signal +

14.9MHz sidebands Phase locked loop

1064nm

Squeezed Light Source

1064nm

vacuum system = photo diode =

PD^allignment

2 axis piezo actuated mirror Squeezing phase

feedback

Bandpass and RMS estimation 3.6-5.4 kHz

11.6Hz

15.2MHz voltage controlled

phase shifter

mirror = generic electronics = electronic oscillator = electronic mixer =

φ

G 1 ( l li ) A i lifi d i l l f h d li h h d i i l d G O 600 hi h

10² 10³

10⁻²² 10⁻²¹ 10⁻²⁰

Frequency [Hz]

Strain [1/√Hz]

No Squeezing Squeezing

−0.50 0 0.5 1 1.5 2 2.5 3 3.5 4

1 2 3 4 5 6 7 8 9 10

Time [days]

Squeezing [dB]

No squeezing Squeezing

PRL 110, 181101 (2013) P H Y S I C A L R E V I E W L E T T E R S week ending 3 MAY 2013

Summary

Quantum Information Science has made much progress and although a practical quantum computers are still in some

distance away (possibly 100 qubits in the next 5 years) there has been spin-off

technology that has made it to the market.

It is the start of seeing useful quantum information technologies. This is the

beginning of the quantum technological

era.

Thank you

www.iqc.ca