QUANTUM INFORMATION:FUTURE OF MICROELECTRONICS?

PAWEL HAWRYLAKQUANTUM THEORY GROUP

INSTITUTE FOR MICROSTRUCTURAL SCIENCESNATIONAL RESEARCH COUNCIL OF CANADA

OTTAWA, K1AOR6,CANADA

CANADIAN INSTITUTE FOR ADVANCED RESEARCHNANOELECTRONICS AND PHOTONICS PROGRAMME

WHY QUANTUM INFORMATION:FUTURE OF MICROELECTRONICS?

CMOS IS A MARVEL OF TECHNOLOGY

YET WITH EXISTING TECHNOLOGY MANY PROBLEMS ARE LIKELY TO REMAIN UNSOLVED:

• QUANTUM MATERIALS• NANOSCIENCE-MULTISCALE PROBLEMS• DRUG DESIGN AND DISCOVERY• HARD MATHEMATICAL PROBLEMS – FACTORIZATION OF

PRIME NUMBERS (SECURITY OF INFORMATION)

HENCE QUANTUM HARDWARE

QUANTUM THEORY AND QUANTUM INFORMATION

QMechanics: EPR, superposition, entanglement, …

Condensed Matter SuperfluiditySuperconductivity Fractional charge FQHEMesoscopics, interferenceQuantum materials????????????

Quantum information:Quantum computing Quantum cryptographyQuantum imagingQuantum sorting…

Materials Science: Correlations,mesoscopics,…

1 1 1 1 1

1 2 3 4 5 6 7 8 9 10 11 12

How Many Configurations? 7925

12

610210

24

7010100

240

Number of atoms on Earth?

Quantum register

|1 1 0 0 1 0 0 1 0 1 0 0 >

QUANTUM THEORY AND QUANTUM INFORMATION

resourcesbits

QUANTUM ABACUS MADE OF HUNDRED BITSIS MORE POWERFUL THAN CLASSICAL ABACUS BUILD OF ALL ATOMS ON EARTH

abacus – 500 AD – 10 additions / min

                                                                                                                                                                            

QUANTUM THEORY AND QUANTUM INFORMATION

|0 0 1 1 0 1 >

QUANTUM INFORMATION 101QUANTUM ALGORITHMS

Spin configuration=|K>

= binary decomposition of number K

QuantumBits,GatesAlgorithm

QUANTUM COMPUTATION

00000|1|)0(| tinitialize

Measure )()(|1 1 TAT

...2|)(1|)()(| 21 tAtAtTime t

Evolve to

final target state 0 T

QUANTUM CRYPTOGRAPHY

QUANTUM HARDWARE AND INFORMATIONDECOHERENCE

•QUANTUM STATES ARE FRAGILE

•ERROR CORRECTION IS POSSIBLE

•OVERHEAD IS VERY HIGH

QUANTUM METROLOGY

QUANTUM NMR……

SOLUTION: FEW QUBITS EMBEDDED IN CLASSICAL SYSTEMS FIRST APPLICATIONS?

QUANTUM ECONOMICS?

QUANTUM INFORMATION APPLICATIONS

FEW QUBITS – EMBEDDED IN CLASSICAL SYSTEMS FIRST APPLICATIONS?

QUANTUM CRYPTOGRAPHY

QUANTUM ECONOMICS

                                                                                                                                                                            

QUANTUM INFORMATION 101APPLICATIONS - QUANTUM ECONOMICS

HP LABS, PALO ALTO

QUANTUM INFORMATION 101APPLICATIONS - QUANTUM ECONOMICS

WHY QUANTUM GAMES?

BIDDING, CONFLICT • ONLY FEW PLAYERS• HIGH PAY-OFF• OF INTEREST NOT ONLY TO PHYSICISTS

“PRISONER DILEMMA” - COOPERATE “C” - DEFECT “D”

QUANTUM GAMEREMOVES DILEMMAOPTIMIZES PAYOFF

Quantum Bidding – 2 Qubits –HP Labs-S.Williams

                                                                                                                                                                            

QUANTUM HARDWAREBUILDING FEW QUBITS IN SOLID STATE

QUANTUM HARDWARE

BUILDING FEW QUBITS IN SOLID STATEUSING MICROELECTRONICS

ELECTRON SPINNUCLEAR SPIN –NMRSUPERCONDUCTIVE QUBITSATOM/ION TRAPSATOM CHIPSLINEAR OPTICS…….

QCOMPUTING WITH QDOTSBarenco et al. 1995Brum PH 1997Loss DiVincenzo 1998

TOWARD ELECTRON SPIN BASED QUANTUM COMPUTER

IN A FIELD EFFECT TRANSISTOR

QComputing with Qdots:Brum&Hawrylak ’97Loss&DiVincenzo ‘98

NANOSCIENCE WITH SINGLE ELECTRONS

ELECTRON SPIN BASED QUANTUM COMPUTER

Model of QComputer : interacting qubits Sjijiii SJSBSH

Effective qubit local field tunable entanglement J

2D electron gas atGaAs/AlGaAs

AlGaAs

90 nm

SOURCE

DRAIN

LOCALISINGCONTROLLED NUMBER OF ELECTRONS 1-100

GaAs

off on

artificialatom

source

drain

NANO SPINTRONICS SINGLE SPIN TRANSISTOR

SINGLE SPIN TRANSISTOR

=2

N=17

ODD NE

CURRENT

ODD NE

B

N=16

N=18

NANO SPINTRONICS SINGLE SPIN TRANSISTOR

Sachrajda,Ciorga,PH,..IMS NRC,PRL’02

1 2IQPC

A.Sachrajda,M.Pioro-Ladriere,PH, Ottawa

(5,0) (6,1) (7,2) (9,4)

(0,0)

(1,1)(1,0)

(0,1)

TUNING TUNELING BARRIER

L.Kouwenhoven et al, DelftS.Tarucha et al TokyoC.Marcus et al, HarvardM.Heiblum et al, Weizman

ELECTRON SPIN BASED QUANTUM COMPUTER

Model of QComputer : interacting qubits Sjijiii SJSBSH

Effective qubit local field tunable entanglement J

ELECTRON SPIN BASED QUANTUM COMPUTERTWO QUBITS

Model of QComputer : interacting qubits Sjijiii SJSBSH

Effective qubit local field tunable entanglement J

1 2IQPC

1 m

(0,0)

(1,0)

(0,1)

V2 / V

V1

/ V

+0.30-0.70

-0.75

0.0

(N1,N2) = (0,0)

(3,0)

(2,0)

(4,0)

(5,0)

(3,1)

(2,1)

(4,1)

(5,1)

(6,1)

(4,2)

(5,2)

(6,2)

(7,2)

(5,3)

(6,3)

(7,3)

(6,4)

(7,4)

(8,4)

(9,4)

(6,5)

(75)

(8,5)

(9,5)

(1,1)(1,2)

(5,4)

(2,3)

(3,3)

(4,3)

(3,4)

(4,4)

(4,5)

(5,5)

A.Sachrajda,M.Pioro-Ladriere,PH PRL2003, PRB2005

(1,0)

ELECTRON SPIN BASED QUANTUM COMPUTERTWO QUBITS-WHY TUNABLE J?

Model of QComputer : interacting qubits Sjijiii SJSBSH

Effective qubit local field tunable entanglement J(1,0)

Loss,DiVincenzo

J12=0 J12>0 J12>0 J12=0t=0 t=T

SPIN SWAPPINGBASIS OF CNOT GATE

…. ….|01> |10>

ELECTRON SPIN BASED QUANTUM COMPUTERCOHERENT CODED QUBIT OPERATION

Swapping spinsRabi oscillationsQuantum Optics on a chip

ELECTRON SPIN BASED QUANTUM COMPUTERTHREE QUBITS-TRIPLE QUANTUM DOT

Model of QComputer : interacting qubits Sjijiii SJSBSH

Effective qubit local field tunable entanglement J(1,0)

-0.40 -0.35 -0.30 -0.25 -0.20

-0.20

-0.25

-0.30

-0.35

5B gate (V)

1B gat

e (V)

-8 -6 -4 -2 0 2

bs

Transconductance left detector sep30100s (minus background)

V5B(V)

V1B(V)

(0,0,0)

(1,1,0)

(0,1,0)

(0,0,1)

(1,0,0)

(0,1,1)

(1,1,1)

-0.25

-0.30

-0.25-0.40

CB

A

A

B

B

A

CBA

IQPC

1B 3B 5B

3T

S

0.5m2B 4B

A.Sachrajda,S.Studenikin,L.Gaudreau,A.Kam, M.Korkusinski, PH, PRL2006

(5,0) (6,1) (7,2)

-0.4100 -0.4050 -0.4000 -0.3950 -0.3900

-0.3750

-0.3775

-0.3800

-0.3825

-0.3850

col

row

6.25 7.50 8.75 10.00 11.25

nov01100s_grey_4_x

-0.375

-0.385

-0.41 -0.39

V5B(V)

V1B(V)

N=3

N=2

N=2

N=2N=3

(1,1,1)

(0,1,2)N=4

N=1

ELECTRON SPIN BASED QUANTUM COMPUTERTRIPLE QUANTUM DOT-CODED QUBIT

Model of QComputer : interacting qubits Sjijiii SJSBSH

Effective qubit local B field tunable entanglement J

M.Korkusinski, PH,SSC2005

S=1/2

)( 321 SSSV

CODED QUBIT

ELECTRON SPIN BASED QUANTUM COMPUTERPROBLEMS AND CHALLENGES

Model of QComputer : interacting qubits Sjijiii SJSBSH

Effective qubit local field tunable entanglement J(1,0)

Single spin – Koppens, Kouwehoven et al,Nature2006 Operation - Pioro-Ladriere, Tarucha et al.

Coherent two spin operation, Single coded qubit operation – Petta,…,Marcus- Koppens, …,Kouwehoven

Coherent spin manipulation over minutes!- Greilich,Bayer,…Science 2006

ELECTRON SPIN BASED QUANTUM COMPUTERPROBLEMS AND CHALLENGES - DECOHERENCE

Model of QComputer : interacting qubits Sjijiii SJSBSH

Effective qubit local field tunable entanglement J(1,0)

DECOHERENCE – NUCLEAR SPINS, SO+PHONONS,IMPURITIES

SOLUTIONS? MATERIALS WITHOUT NUCLEAR SPIN

2-6, CARBON NANOTUBES, GRAPHENE?

LOCALIZED VS ITINERANT ELECTRONSHUBBARD MODEL

A WINDOW ON QUANTUM MATERIALS:

COMPLEX OXIDES WITH TRIANGULAR LATTICE

NaxCO2

TRIPLE QDOT MOLECULESSPIN, TOPOLOGY, STATISTICS AND E-E CORRELATIONS

triplet singlet

Exchange Vx

~Vx~e^2

S=0

S=1

21

21

21

21

Singlet – double occupancy

Super-Exchange

~4t^2/U~1/e^2 S=0

S=1

t

TRIPLE QDOT MOLECULESSPIN, TOPOLOGY, STATISTICS AND E-E CORRELATIONS

0|

12ccA

0|23 ccC

32

1

32

1

321213

123123

132321

ˆ

EEtt

tEEt

ttEE

H

triplet

TRIPLE QDOT MOLECULESSPIN, TOPOLOGY, STATISTICS AND E-E CORRELATIONS

0|

13ccB

32

1

321213

123123

132321

ˆ

EEtt

tEEt

ttEE

H

singlet

PH,Korkusinski,SSC2005

S=1SINGLET GS!TOPOLOGICAL “HUNDS” RULE!SPIN-CHARGE SEPARATION?

S=0

~t

TRIPLE QDOT MOLECULESFILLING LOWEST ELECTRONIC SHELL

3t

3t

3t

2e SINGLET

4e TRIPLET

3t4e SINGLET

Voltage tunable nano-magnet-1V

-1.1V -1.1V

-2.5V -2.5V

0V 0V

0V

Korkusinski,Puerto,PH….. PRB2007

QUANTUM INFORMATION APPLICATIONS

FEW QUBITS – EMBEDDED IN CLASSICAL SYSTEMS FIRST APPLICATIONS?

QUANTUM CRYPTOGRAPHY – QUANTUM KEY DISTRIBUTION

SINGLE PHOTONS-SECURE-NO CLONING-SHORT DISTANCE

ENTANGLED PHOTON PAIRS-QUANTUM REPEATER-LONG DISTANCE

ENABLING TECHNOLOGY FOR QUANTUM CRYPTOGRAPHY:

•SOURCE OF SINGLE PHOTONS ON DEMAND

•SOURCE OF ENTANGLED PHOTON PAIRS

QUANTUM INFORMATIONQUANTUM CRYPTOGRAPHY-WHATS NEEDED?

ENABLING TECHNOLOGY :SELF-ASSEMBLED QUANTUM DOT DEVICES

QUANTUM DOT TECHNOLOGY REQUIREMENTSFOR QUANTUM CRYPTOGRAPHY:

•EMISSION AT TELECOM WAVELENGTH-MATERIALS

•ENHANCED LIGHT MATTER INTERACTION-QDOTS IN PHOTONIC CAVITIES

-PRECISE POSITIONING OF QDOTS

•ENGINEERING OF LIGHT POLARIZATION-FULL UNDERSTANDING OF AND ABILITY TO ENGINEER

OPTICAL PROPERTIES OF QDOT

QUANTUM INFORMATIONQUANTUM CRYPTOGRAPHY

STRAIN DRIVEN SELF-ASSEMBLY: InAs/GaAs

DIRECTED SELF-ASSEMBLY VIA LITHOGRAPHY: InAs/InP at 1.5m SiO2

mask InAs dot

InP pyramid

ARTIFICIAL ATOM FACTORY

GROWTH AND POSITIONING OF QDOTS EMITTING AT TELECOM WAVELENGTH

Williams,Poole,…IMS

GROWTH AND POSITIONING OF SINGLE QDOTS GATING OF A SINGLE QDOT

M.Reimer,J.Lapointe,P.Poole, R.Williams,…

EXTRACTING SINGLE PHOTONSSINGLE QUANTUM DOT IN A CAVITY

InAs dot

InP pyramid

sa

saQ>8000

TuningPhotonFieldInsidecavity

Dalacu,Aers,Williams, Poole

POSITIONING DOTS INE-FIELD MAXIMA

ENTANGLED PHOTON PAIRS FROM EXCITON TO BI-EXCITON CASCADE

QUANTUM INFORMATIONQUANTUM CRYPTOGRAPHY

Entangled Photon Pairs From a Semiconductor Quantum Dot, Akopian, Gershoni, Avron, Petroff,……PRL 2006

ORSPLITTING

QUANTUM INFORMATIONQUANTUM CRYPTOGRAPHY-MATERIALS CHALLENGE

InAs/InP

NICE,PROOF OF CONCEPT,BUT NOT AT TELECOM WAVELENGTH!~0.8eV

InAs/GaAs

(8,5)

0.80 0.85 0.90 0.95 1.00 1.05

1.70

1.65

1.60

1.55

Emission energy (eV)

Exci

tatio

n en

ergy

(eV)

4000 8000

Lefebvre,Finnie,IMS

jiji

ii

SJS

BSH

TOWARD QUANTUM INFORMATION WITH QUANTUM DOTS

““Crossing”Crossing”

(8,5)

0.80 0.85 0.90 0.95 1.00 1.05

1.70

1.65

1.60

1.55

Emission energy (eV)

Exc

itatio

n en

ergy

(eV

)

4000 8000InAs dot

InP pyramid