From Quantum Science to Quantum Technologies Message

Raymond Laflamme [email protected] www.iqc.ca From Quantum Science to Quantum Technologies 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 Curiosity

Social Impact Understanding

Technology Control 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

Plus !! Discovery of how to control quantum systems • DevelopmentProof-of-concepts of practical experiments quantum information technologies • On the first floor … Nano Center Lazaridis Quatnum University of Waterloo University of Waterloo Mike and Opehlia Quantum Technologies today Made possible because the world in quantum

Lasers LEDs

MRI Transistors Quantum Information: The QUBIT

Spin-based QIP Trapped Ions Superconducting Qubits

Quantum Optics Trapped Atoms Quantum Dots 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 13 Cl Cl C1 N S NMR quantum computing =|010> 13 C H 2 Cl Trichloroethylene Brief history of NMR Bloch and Purcell

Applications of NMR -MRI -molecular structure -chemical analysis -concrete research -tire compositions - molecular dynamics -… Cl H1

S C5 C4 H Cl 3 NMR quantum computing C3

H2 C6 C7 C2 O H 5 H4

C1 O O Brief history of QIP achievements H

•! laboratory feedback on quantum control •! theoretical challenges: DQC1 John Waugh 1 (I + αZ) 2 n I⊗ 2n •! development of experimental QECorrection •! … -push the quality of quantum control Challenge with inhomogeneity

B+!B B B-!B

"B+!B > "B > "B-!B

0 Z A rf inhomogeniety selective pulse " Y X ! Find a pulse sequence that keep the spins that are within a given homogenity bound and spread the other around the sphere 1

1 z 0.8

0.6

0.4

0.2 # of spins

-1 1 2 3 y i rf inhomogeneity x i

64 1.0 Rx(90) R x(180)) 0.8 ! ! 0.6 64 0.4 (Ri (180)R i (180)) Ry(90) 0.2 amount of signal ! 1.5% 3.0% 4.5% 6.0% 7.5% rf inhomogeneity

NMR Oil well logging

Application to oil well logging by measuring presence of • water/oil ! Small pore Large pore

•! porosity of rocks • motion of the liquid Amplitude ! Amplitude

MRIL® Magnetic Resonance ImagingTime, Logging msec Time, msec

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 … http://www.halliburton.com

N S Measuring a magnetic field 0 Z 1 t+τ /2 " Y φ(t, τ )= µB(t)dt X t τ /2 − ! Ψ(φ(t, τ )) = 0 + eiφ(t,τ ) 1 1 | | z z z precession (t-� /2,t) y y y P rob( 0 0 )=Cos[φ(t, τ )] x x x | |

1 z z z Cos[F] �spin-echo �spin-echo precession 0.5 y y (t,t+� /2) y 5 10 15 20 25 30 x x x -0.5

-1 F Technology comparison

MRFM (2004)

MRFM (2007)

SQUIDS (2008) MRFM (2009) Atom chip (2005)

10-8 10-6 10-4 10-2 100 Distance [m] 10nm 1!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 Potential Energy

2 x /2 2 E=hN LdQ 1 1 1 E = + Q2 = Φ2 + Q2 E=hN 2 dt 2C 2L 2C E=hN

X or &

1 1 E = p2 + (q Λ)2 2 2 − Λ is the control parameter charge qubit Λ = Vg gate voltage phase qubit Λ = I ← bias current ﬂux qubit Λ = Φ ← external ﬂux ext ← 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

100 Josephson junction 1 1 80 E = Φ2 + Q2 2L 2C 60 a) 40 20 + Ej cos(2πΦ/Φ0) -10 -5 5 10

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

Scientific American, Energy diagram

October 2007

! ! Explain how they work and the achievement of Yacoby

NV centers a Excitation laser |1〉 2γ B Scanning diamond |–1〉 Yacoby, Nature Physics 9, 215, 2013 platform ωMW

|0〉 MW coil Sensor NV z

x y Target spins

50 nanometer above target

Measure single spin Electron spins:

“long coherence time” -> electronic resolution: 2.7 Å -room temperature -can initialized the qubit Nuclear spins: -measure electron spin resonance -> nuclear resolution: 6 Å

Quantum sensors

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

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 Neutron interferometry -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 Pn~(1 e)n: 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 this state state is not is invariant invariant wrt rotations

+ | ↑↓ − | ↓↑ | ↑↓ | ↓↑ Neutron interferometry an example of macroscopic quantum coherence

2 2 4 IO = "O = t r [1+ cos(#)] Measure the neutron Intensity. In this case that is the number of neutrons per unit time.

= " 2 = 2 4 + 4 # 2 2 $ IH H r [(t r ) r t cos( )]

Neutron interferometry an example of macroscopic quantum coherence

Measure the neutron Intensity. |0> In this case that is the number of neutrons per unit time.

|1> 1 1

1 3 4 1

2 4 3 2

2 2 |00>

1 1 |0> |01> 1 3 4 1

|10>

2 4 3 2 |1>

|11>2 2 |0> |01> 1

3 4 1 |10>

2 4 3 2 |1> Neutron interferometry

The 4/5 blade interferometer a robust again rotation No vibration 3 blade 8 Hz vibration 650

600

550 a b (220) 500 + beam blocks Neutr ons per 300 sec phase flag 450

O-beam

-1.5 -1.0 -0.5 0.0 0.5 1.0 1.5 H-b eam neutron Phase flag rotation, (°) beam blocks detectors b 700 No vibration 4 blade 650 8 Hz vibration

600

550 on beam 500 neutr 450 perfect Si single crystal interferometer Neutr ons per 300 sec 400

c 350 neutron interferometer enclosure -1.5 -1.0 -0.5 0.0 0.5 1.0 1.5 beam motor Phase flag rotation, (°)

low frequency vibration isolation table off-center mass off-center

vibration vibration isolation pads isolation pads 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

Potential Energy

x2 /2 E=hN Ground state E=hN

E=hN

X or & P X

Uncertainty relations Squeezed Ground state ∆X ∆P /2 × ≥

P X 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 GEO600: gravitational wave detector

MFn vacuum system =

2 sequential photo diode = mode-cleaners mirror = (8m round-trip) 600m north arm (folded in vertical plane) generic electronics =

electronic oscillator = Injection locked high-power MCn 600m east arm electronic mixer = laser system MPR (folded in vertical plane) T=0.09% 1064nm

MCe BS MFe

MSR OMC Michelson output signal + T=10% Data output Phase locked loop 14.9MHz sidebands Faraday h(t) Isolator

Squeezed Bandpass and Light Source Squeezed vacuum + RMS estimation 3.6-5.4 kHz 15.2MHz subcarrier field PDallignment 1064nm

2 axis piezo actuated mirror

Squeezing phase feedback φ voltage controlled 15.2 MHz phase shifter 11.6 Hz

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

week ending PRL 110, 181101 (2013) PHYSICAL REVIEW LETTERS 3 MAY 2013

−20 10 10 No Squeezing Squeezing 9

8 No squeezing

7 Squeezing

6 Hz] √ −21 10 5

Time [days] 4 Strain [1/ 3

−22 0 10 2 3 −0.5 0 0.5 1 1.5 2 2.5 3 3.5 4 10 10 Squeezing [dB] Frequency [Hz] 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