ULTRA-PRECISE CLOCK SYNCHRONIZATION VIA DISTANT ENTANGLEMENT

Selim Shahriar, Project PIFranco Wong, Co-PIRes. Lab. Of Electronics

DARPA QUantum Information Scienceand Technology

May 2004 / Chicago

Selim Shahriar, subcontract PIDept. of Electrical and Computer EngineeringLaboratory for Atomic and Photonic TechnologiesCenter for Photonic Communications and Computing

Ulvi Yurtsever, “subcontract” PIJet Propulsion Laboratory

Http://lapt.ece.nwu.edu/research/Projects/clocksynch

Dr. Marco Fiorentino, Dr. Frieder Konig,Taehyun Kim (GS)

Dr. George CadosoDr. Prabhakar PradhanDr. Venkatesh GopalDr. Gaur TripathiKen Salit (GS)Jacob Morzinski (GS)Ahmed Hasan (US)

Dr. John DowlingDr. Chris AdamiDr. Robert GringichDr. Attila BergouDr. Hwang LeeDr. Demetri Strekalov

POGRAM SUMMARY

Picosecond scale synchronization of separated clocks, and remote frequency-locking will increase the resolution of GPS systems

Quantum memory will be produced with a coherence time of upto several minutes, making possible high-fidelityquantum communication and teleportation

Sub-pico-meter scale resolution measurement of amplitudeas well as phase of oscillating magnetic fields would enhance the sensitivity of tracking objects such as submarines

Non-deg Teleportation

Bloch-Siegert Oscillation

Frequency Teleportation

Relativist Entanglement

Decoherence in Clock-Synch

YR1 YR3YR2

Entangled Photon Source

CLOCK A CLOCK B

f

TRAPPED RB ATOM QUANTUM MEMORY

ULTRA-BRIGHT SOURCE FOR ENTANGLEDPHOTON PAIRSDEGENERATE DISTANT ENTANGLEMENT BETWEEN PAIR OF ATOMSQUANTUM FREQUENCY TELEPORTATION VIA BSO AND ENTANGELEMENTRELATIVISTIC GENERALIZATION OF ENTANGLEMENT AND FREQUENCY TELEPORTATIONSUB-SHOT-NOISE TIME SIGNALING VIA ENTANGLEDFREQUENCY SOURCE

POTENTIAL BENEFIT

PROJECT ELEMENTS

TIMELINE OF EFFORT

Entanglement variation can be used to account forRelativistic ---including Doppler --- effect withoutHaving to measure velocity separately, thus increasingAccuracy of Time Transfer

tt1 t2

A

1

3

THE BLOCH-SIEGERT OSCILLATION

“Driver Phase Correlated Fluctuations in the Rotation of a Strongly Driven Quantum Bit," M.S. Shahriar, P. Pradhan, and J. Morzinski, to appear in Phys. Rev. A

KEY STEP OF PROTOCOL: USE BSO SIGNATURE TO TELEPORT PHASE INFORMATION

A

1 2

3

B

1 2

3

BAt 31)(

t

t

ALICE:

BOB:

t3 t4

t1 t2

t5 t6

t7 t8

BABA

t 2

1)( BA

t 1)(

RESULT OF THE PROTOCOL:

BOB

f

“Physical Limitation to Quantum Clock Synchronization,” V. Giovanneti, L. Maccone, S. Lloyd, and M.S. Shahriar, Phys. Rev. A 65, 062319 (2002)

“Wavelength Teleportation via Distant Quantum Entanglement Using the Bloch-Siegert Oscillation ” M.S. Shahriar, P. Pradhan, V. Gopal, J. Morzinski, G. Cardoso, and G.S. Pati under review for Physical Review Letters

0.35 mm hole

Rb

Oven

1 mm hole~1 mm~1 mm

Liquid N2 Cold Trap

4.5 mm

7 mm

16.5 mm

RF coil

Nozzle Collimator

~15 cm ~15 cm

Fluorescence

Imaging lens

uB(t)

Atomic beam

Opticalpumping

APD

Probe beamRF coil

EXPT APPARTUS FOR OBSERVATION OF BSO USING RB ATOMIC BEAM

USE ZEEMAN SUBLEVELS

THERMAL VELOCITY SPREAD DOESNOT CAUSE BSO WASHOUT

REASON: BSO MAPS PHASE AS SEENBY AN ATOM AT THE LOCATION ANDTIME IT IS DETECTED --- VIA FLUORESCENCE

BSO FOR AN RF-EXCITED THREE LEVEL SYSTEM

F=1, m=-1

F=1, m=0

F=1, m=+1 m=0

F=1, m=-1

F=1, m=0

F=1, m=+1 m=0

F=1, m=-1

F=1, m=0

F=1, m=+1 m=0

F=1, m=-1

F=1, m=0

F=1, m=+1 m=0

F=1, m=-1

F=1, m=0

F=1, m=+1 m=0

F=1, m=-1

F=1, m=0

F=1, m=+1 m=0

2-LEVEL

3-LEVEL

EXPERIMENTAL SETUP FOR ANALYZING RABI-FLOPPING AND BSO

6061A RF synthetizer 1

Freq. = f

50 WAmplifier

Standing Wave meter

Coil around atomic beam

Fluorescence

APD13.5*105 V/W

SR560 1 MHzPreamp and filters

6061A RF synthetizer 2Freq. = f +

Correlated within10 Hz

Low-pass filter

Sin(t(scope)

Spectrum Analyser

Fluorescence spectrum(scope)

Phase syncronization

BSO signal Rabi flopping

6061A RF synthetizer 1

Freq. = f

50 WAmplifier

Standing Wave meter

Coil around atomic beam

Fluorescence

APD13.5*105 V/W

SR560 1 MHzPreamp and filters

6061A RF synthetizer 2Freq. = f +

Correlated within10 Hz

Low-pass filter

Sin(t(scope)

Spectrum Analyser

Fluorescence spectrum(scope)

Phase syncronization

BSO signal Rabi flopping

Atomic Beam

Probe Laser

Lens

APD

RF

Bo sin (t +)

Io sin (2t +2)

Atomic Beam

Probe Laser

Lens

APD

RF

Bo sin (t +)

Io sin (2t +2)

Lens

APD

RF

Bo sin (t +)

Io sin (2t +2)

0 2 4 6 8 10

Ato

mic

Flu

ores

cenc

e (a

rb. u

nits

)

Time (s)

F=2

F=1

RF

F=1

F=1

RF

F=0

F=1trigger

Atomic Beam

Probe Laser

Lens

APD

RF

RF source frequencydoubler

oscilloscope

signal

DIRECT OBSERVATION OF THE BSO AT 2 IN REAL TIME

0.0 1.0 2.0 3.0 4.0

Ato

mic

Flu

ores

cenc

e (a

rb. u

nits

) (b)(a)

0.8T

Time (s)

trigger

Atomic Beam

Probe Laser

Lens

APD

RF

RF source frequencydoubler

oscilloscope

signal

0.4T delay line (a)

DIRECT, LOCALIZED MEASUREMENT OF PHASE OF RF FIELD

“In-Situ Observation of the Absolute Phase of a Microwave Field via Incoherent Fluorescence Detection" G. Cardoso, P. Pradhan, and M.S. Shahriar, under review for Nature.

TRAPPED ATOM FOR REMOTE ENTANGLEMENT

TS

L1

IMAGE INTENSIFIEDCCD CAMERA

DET

FIBER FORT

TWO SEPARATE TRAPS FOR ALICE AND BOB

FORT

MOT

LAUNCH

QMG

FORT

MOT

LAUNCH

QMGFORT

MOT

LAUNCH

FORT

MOT

LAUNCH

MOT

LAUNCH

“Long Distance, Unconditional Teleportation of Atomic States Via Complete Bell State Measurements,” S. Lloyd, M.S. Shahriar, J.H. Shapiro and P.R. Hemmer, Phys. Rev. Letts.87, 167903 (2001)

|a>

|b>

L L

d

vx

π/2 π

π/2

1 1 1

2 22

1

2

BCI

CI

|a>

|b>

x

z

|a>

|b>

L L

d

vx

π/2 π

π/2

11 11 11

22 2222

11

22

BCI

CI

|a>

|b>

x

z

A SINGLE-ZONE, CONTINUOUS ATOM-INTERFEROMETER

“Continuously Guided Atomic Interferometry Using a Single-Zone Optical Excitation: Theoretical Analysis," M.S. Shahriar, M. Jheeta, Y. Tan, P. Pradhan, and A. Gangat, under review for Physical Review A.

A SINGLE-ZONE, CONTINUOUS ATOM-INTERFEROMETER

0 0.005 0.01 0.015 0.020.02

0

0.02

0.04

0.06

0.08

0.10

0.12

0.14

0.16

Distance x (m)

CO

M D

ispl

acem

ent (m

)

|a>

|b>

|a>

|b>

-2

-1.5

-1

-0.5

0

0.5

1

1.5

2

-1 0 1

l/l

η

0 0.005 0.01 0.015 0.020.02

0

0.02

0.04

0.06

0.08

0.10

0.12

0.14

0.16

Distance x (m)

CO

M D

ispl

acem

ent (m

)

|a>

|b>

|a>

|b>

0 0.005 0.01 0.015 0.020.02

0

0.02

0.04

0.06

0.08

0.10

0.12

0.14

0.16

Distance x (m)

CO

M D

ispl

acem

ent (m

)

|a>

|b>

|a>

|b>

-2

-1.5

-1

-0.5

0

0.5

1

1.5

2

-1 0 1

l/l

η

-2

-1.5

-1

-0.5

0

0.5

1

1.5

2

-1 0 1

l/l

η

AA

BB

a

b

3035 MHz

121 MHz

F=3

F=2

DOP

R1

R2

F’=4F’=3

1517.5 MHz

OP GALVOSCANNER

D

PM

T

R1

R2A

B

DEMONSTRATION OF THE SINGLE-ZONE, CONTINUOUS ATOM-INTERFEROMETER

-0.0095 -0.0090 -0.0085 -0.0080 -0.0075

Unit: SecU

nit:

Arb

Uni

t: A

rb

A

B

-0.0095 -0.0090 -0.0085 -0.0080 -0.0075

Unit: SecU

nit:

Arb

Uni

t: A

rb

AA

BB

Phase Scan

Atom Interferometer

M-Z Interferometer

Rotation at rate causes fringe minimum to shift by

“Demonstration Of A Continuously Guided Atomic Interferometer Using A Single-Zone Optical Excitation," M.S. Shahriar, Y. Tan, M. Jheeta, J. Morzinksy, P.R. Hemmer and P. Pradhan, under review for Phys. Rev. Letts

THE SINGLE-ZONE INT REVISITED: TWO-LEVEL MODEL

|a, 0>=|A>

|e, k >=|E>

At Start: |> = |A> |1>

After Excitation:

|> = Cos(/2)|A> |1> + Sin(/2)|E> |0>

= 2 U m /

* Replace 2-lev with 3-lev system in practice

** Replace single atom with ensemble possibly

“Single-Photon, Single-Atom Interferoemetry for Entangling Macroscopic Rotors,“M. S. Shahriar, P. Pradhan, and R. Nair to be submitted to Phys. Rev. Letts.

SINGLE-ZONE ATOM-INTERFEROMETRY FOR FREQUENCY LOCKING

Bob

Alice

a b

a b

A

B

EPP-Source

A-Clock A

B-Clock B

Post-Selection Correlation: Cos[B-A) ]

Enables Asynchronous Frequency Locking

Will Require Ensemble Interaction to Enhance Single Photon Coupling Rate

Summary on entanglement sources

• Demonstrated an ultrabright source of polarization-entangled photons– Total output flux is entangled without spectral, spatial, or

temporal filtering– novel configuration with bi-directional pumping and collinear

propagation– 795-nm center wavelength for coupling to trapped Rb

• Demonstrated extended phase matching in PPKTP– 100 nm phase-matching bandwidth for second harmonic

generation– setting up to demonstrate coincident-frequency entanglement

and full recovery of HOM dip in pulsed pumping

Ultrabright dual-pump downconversion source

…with a new twist

PPKTP source• Type-II collinear downconversion• One crystal with bi-directional pumping• Outputs are completely indistinguishable• Entanglement is independent of direction of

emission and wavelengthPPKTP

Split pump

I1

I2S1

S2

|HV + ei |VH2

| =

An old idea…• Combine two identical sources

|HV + ei |VH2

| =

Dual-pump SPDC experimental setup

UV pump interferometercontrols the phase :

singlet or triplet

quant-ph/0309071

P P K T P

S 1

I 1

I 2

S 2

Id ler

U Vd etecto r

C o u n ter-p ro p a g a tin g p u m p s

P B S

In terferen ce filter

Ir is

P o la r iza tio n a n a ly zer

H W P

Characteristics of dual-pump SPDC

0.5

0.6

0.7

0.8

0.9

1

0 1 2 3 4 5 6 7 8 9Iris diam eter (m m )

0

4000

8000

12000

16000

0 2 4 6 8 10

Iris diam ete r (mm )

0.7

0.75

0.8

0.85

0.9

0.95

1

79 4 79 6 79 8 80 0Signa l w ave len gth (n m)

Id ler wavelength (nm )

79 8 79 680 0 79 4

Vis

ibili

ty

Coi

n. c

ount

s (s

mW

)

Vis

ibil

ity

High flux Wavelength independent

Almost independent of aperture size

Quality of dual-pump polarization entanglement

0

1000

2000

3000

4000

5000

6000

-150 -100 -50 0 50 100 150 200 250

deg

Coi

ncid

ence

s/s

Bell’s inequality measurements

0.76 mW pump power; 3-nm filter; aperture size = 3.1 mm

S = 2.599 ± 0.006

SUMMARY OF PROGRESS

Demonstration of Launch and catch FORT, as precursor to singletrapped atoms

Observation and Analysis of BSO in an atomic beam under multi-level excitation

Demonstration of A Compact, High Flux Source for Polarization Entangled Photon Pairs at 795 for Entangling Rb Memory Elements

Developed Model For How Entanglement Variation Can Be Used To Infer Relativistic Effects And Correct For Them

Construction of a Pair of Integrated Cavity-Fort for Remote Frequency Locking

Demonstration of a Single-Zone Atom-Interferometer

Developed a Model for Using a Frequency Entangled Source For Enhanced-Accuracy Timing Measurement

Developed Technique for Producing The Frequency Entangled Source

Built a Pair of Traps for Single Atom Plus Cavity for Freq Teleportation Developed Technique for Freq Teleportation via Single Atom Interferometry

“Long Distance, Unconditional Teleportation of Atomic States Via Complete Bell State Measurements,” S. Lloyd, M.S. Shahriar, J.H. Shapiro and P.R. Hemmer, Phys. Rev. Letts.87, 167903 (2001)

“Wavelength Teleportation via Distant Quantum Entanglement Using the Bloch-Siegert Oscillation ” M.S. Shahriar, P. Pradhan, V. Gopal, J. Morzinski, G. Cardoso, and G.S. Pati under review for Physical Review Letters

“Physical Limitation to Quantum Clock Synchronization,” V. Giovanneti, L. Maccone, S. Lloyd, and M.S. Shahriar, Phys. Rev. A 65, 062319 (2002)

“Driver Phase Correlated Fluctuations in the Rotation of a Strongly Driven Quantum Bit," M.S. Shahriar, P. Pradhan, and J. Morzinski, to appear in Phys. Rev. A.

MOST RELEVANT PUBLICATIONS/PREPRINTS

“In-Situ Observation of the Absolute Phase of a Microwave Field via Incoherent Fluorescence Detection" G. Cardoso, P. Pradhan, and M.S. Shahriar, under review for Nature.

“Super Efficient Absorption Filter for Quantum Memory using Atomic Ensembles in a Vapor," A. Heifetz, A. Agarwal, G. Cardoso, V. Gopal, P. Kumar, and M.S. Shahriar, to appear in Optics Communications

“Continuously Guided Atomic Interferometry Using a Single-Zone Optical Excitation: Theoretical Analysis," M.S. Shahriar, M. Jheeta, Y. Tan, P. Pradhan, and A. Gangat, under review for Physical Review A.

“Demonstration Of A Continuously Guided Atomic Interferometer Using A Single-Zone Optical Excitation," M.S. Shahriar, Y. Tan, M. Jheeta, J. Morzinksy, P.R. Hemmer and P. Pradhan, under review for Phys. Rev. Letts

“Single-Photon, Single-Atom Interferoemetry for Entangling Macroscopic Rotors,“M. S. Shahriar, P. Pradhan, and R. Nair to be submitted to Phys. Rev. Letts.

"Negligible Bloch-Siegert oscillation in an effective two level Lambda system : An advantageous platform for fast and precise rotation of a qubit," P. Pradhan, G. Cardoso, J. Morzinski, and M.S. Shahriar , under review for J. Opt. Soc. Am. B.

R. Jozsa, D.S. Abrams, J.P. Dowling, and C.P. Williams, Phys. Rev. Letts. 85, 2010(2000)

U. Yurtsever and J.P. Dowling, “ Lorentz-invariant look at quantum clock synchronization protocols based on distributed Entanglement,”quant-ph/0010097

V. Giovannetti, S. Lloyd, L. Maccone, and F.N.C. Wong,"Clock Synchronization with Dispersion Cancellation," Phys. Rev. Letts. 87, 117902 (2001)

Robert M. Gingrich and Christoph Adami "Quantum Entanglement of Moving Bodies," Physical Review Letters, 89, 270402 (2002)

Attila J. Bergou, Robert M. Gingrich, and Christoph Adami "Entangled Light in Moving Frames," To appear in Phys Rev. A.

Ulvi Yurtsever "The Holographic Entropy Bound and Local Quantum Field Theory", http: //xx.lanl.gov/abs/gr-qc/0303023

“Generation of ultrabright tunable polarization entanglementwithout spatial, spectral, or temporal constraints,” Marco Fiorentino,. Ga´etan Messin, Christopher E.Kuklewicz, Franco N. C. Wong, and Jerey H. Shapiro, submitted to Phys. Rev. Letts