Quantum Memory For Teleportation And the Quantum Internet
Team:Ahmed Hasan (Undergrad Student)Ken Salit (Graduate Student)Jacob Morzinski (Graduate Student/MIT)Dr. Venkatesh Gopal (Post-Doc)Dr. Gaur Tripathi (Post-Doc)Prof. Philip Hemmer (Texas A&M: Visitor)
Supported By:ARO, ARDA
BASIC OBJECTIVES
Demonstrate A Quantum Memory Unit (QMU) In the Form of a Single Rb Atom Trapped Inside a High Finesse Cavity
Demonstrate Transfer of Photon Entanglement to a Pair Of QMU’s.
Demonstrate Quantum Teleportation via Measurement ofAll the Bell States
“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)
TELEPORTATION: WHAT
EARTHALPHA-CENTAURI
| |BEFORE...
AFTER...
||
BOB
ALICE
||
| |W||||
BELL STATES
||||
DECOMPOSITION
||||||||
TELEPORTATION: VIA BELL STATE MEASUREMENT
BOB
ALICE
|
| |W||||||||
| |
|
| |-1 0
0 1|
| |0 1
1 0|
| |0 -1
1 0|
| |
WHERE
NB
Time
|B>
|E>
|A>
LASER-CONTROLLED SPIN EXCITATION OFF-RESONANT
GOOD FOR SINGLE BIT OPERATION
|E>
(|A> + |B>)|+>=(|A> - |B>)|->=
|B>
|E>
|A>
LASER-CONTROLLED SPIN EXCITATION RESONANT
NE
(SS)
0EXPT. IN Rb TWO-PHOTON DETUNING
|e
|a|b
21
THE DARK STATE:: GENERAL CASE
12
22
|e
|e
|a|b
1 3
|e
|a|b
|e
|a|b
3 1
|e
|a|b
1 1
|e
|a|b
1
0
AM
PL
ITU
DE
TIME
|a> - |e> |b> - |e>
|a> + |e> |b> + |e>
|->=|b> |->=|a>
|+> - |e>
|+> + |e>
|-> = (2|a> - 1|b>)/|+> = (1|a> + 2|b>)/
|e
|a|b
|e
|- |+
ADIABATIC TRANSFER VIA THE DARK STATE
TOPOLGICALLY ROBUST
EQUIVALENT TO A -PULSE
ATOM A
ATOM B
1 2
g
A B
0
g2
g1
A B
0
COHERENCE TRANSFER VIA CAVITY QED
2
1
0
1
INT
EN
SIT
Y
TIME
1 2
1 2
g
ATOM 1 ATOM 2
|a1> |b1>
|e1>
1 g
|a2> |b2>
|e2>
2 g
|a1 b2 0> |b1 a2 0>
1 g 2g
|b1 b2 1>
|e1 b2 0> |b1 e2 0>
2 g 1 g12
ONE CAVITY PHOTON
|b1 b2 0>
NO CAVITY PHOTONS
ADIABATIC COHERENCE TRANSFER VIA CAVITY-QED DARK STATE
||a1>|b1>) |b2> |0>
||b1 a2 0>|b1b20>) = |b1> |a2 >|b2>) |0>
e p
2
0
2
0
g
2
g
2
01
1
0
g
1
g
1
0
0
1 2
1 2
1 2
1 2
e p
ATOM B
2
2
ATOM A
1
1
ATOM A
ATOM B
TRANSFERRING TWO BITS INTO A SINGLE ATOM VIA CAVITY QED
TRANSFER PHOTON ENTANGLEMENT TO ATOMIC ENTANGLEMENT
EXPLICIT SCHEME IN 87RBC
A
B
D
ATOM 1 IN ARBITRARY STATE: TO BE TELEPORTED
|1> ={|c>1+|a>1}
a b
c d
a b
c d
a b
c d
ATOMS 2 AND 3 ARE FIRST ENTANGLED USING THE PHOTON-CAPTURE PROCESS
|23>={ |a>2|b>3 - |b>2|a>3}/2
a b
c d
a b
c d
COMPLETE STATES OF ALL THREE ATOMS
|1> ={|c>1+|a>1}
|23>={|a>2|b>3 - |b>2|a>3}/2a b
c d
a b
c d
a b
c d
e n
2
0
2
0
g
2
g
2
01
1
0
g
1
g
1
0
0
1 2
1 2
1 2
1 2
e n
ATOM B
2
2
ATOM A
1
1
ATOM A
ATOM B
TRANSFERRING TWO BITS INTO A SINGLE ATOM VIA CAVITY QED
TRANSFER STATES OF 1 AND 2 INTO 2 ONLY
QUANTUM STATE AFTER THE TRANSFER
|1> ={|c>1+|a>1}
|23>={|a>2|b>3 - |b>2|a>3}/2
a b
c d
a b
c d
a b
c d
BEFORE TRANSFER
|A>={|c2>|b2>}/2, |B>={|d2>|a2>}/2.
|23>={|A+>(|b3>+|a3>) + |A->(|b3>-|a3>) + |B+>(|b3>+|a3>)+ | B->(-|b3>+|a3>)}/2
AFTER TRANSFER
|1> = |c>1
BELL STATES
ROTATE SUPERPOSITION-BASIS BELL STATES INTO PURE-BASIS BELL STATES
a b
c d
|A+>=|c2>+|b2> |A->=|c2>-|b2>|B+>=|d2>+|a2> |B->=|d2>-|a2>.
OLD BELL STATES
pulses
a b
c d
|a+>=|c2> |a->=|b2>|b+>=|d2> |b->=|a2>.
NEW BELL STATES
MEASURING BELL STATES VIA SEQUENTIAL ELIMINATION
THE QMU
FORT Beam
Cavity FieldRb Atom
THE MACHINERY
TS
L1
VALVE
VALVEO
VE
N S
EC
TIO
N: H
V
MAIN CHAMBER: UHV
LAUNCH BEAM: TSL1
S-D
L
TS
L2
UPPER CHAMBER: UHV
TS
L3
F'
F
1
2
3
4
2
3
5S1/ 2
5P3/2
780.1 nm
3036
29.3
63.4
120.7
Fig. 2
1 2
3
THE CAVITY AND THE FOUNTAIN
Launch laser beam
Pulsed ServoBeam
Pulsed Probe Beam
FORTBeam
Copper Block For Vibration Isolation
STABILIZING THE CHIRP
DIODELASER
DIFFERENTIATOR
MULTIPLIER DELAY PULSE GENERATOR
INTEGRATORADDER
LASERCONTROLLER
BS
TOEXPERIMENT
ABSORPTION CELL
F'
F
1
2
3
4
2
3
5S1/ 2
5P3/2
780.1 nm
3036
29.3
63.4
120.7
1 2
Frequency Stabilization of an Extended Cavity Semiconductor Laser for Chirped Cooling,” J.A. Morzinsky, P.S. Bhatia, and M.S. Shahriar, to appear in Review of Scientific Instruments
REALIZING THE FOUNTAIN LAUNCH
LAUNCH BEAM: TSL1
TS
L1
~2mm
Adjustableheight
AOM 1
AOM 2
AOM 3
To sat. abs.locking
To trap
Launch beam
Timers
on/off
on/off
on/off
Magneticfield
TSL1
DET
REALIZING THE FOUNTAIN LAUNCHLaunch Fluorescence, 2 mm Height
LAUNCH BEAM: TSL1
TS
L1
Adjustableheight
DET
Magnetic field
Trap laser
Launch laser
onoff
onoff
onoff
300 ms
3 ms 100 ms
5 ms 100 ms
1 2 3 4 5 6 7 8 9
x 10-3
0
0.2
0.4
0.6
0.8
1
Time (sec.)
De
tect
or
Vo
ltag
e (
V)
REALIZING THE FOUNTAIN LAUNCHLaunch Fluorescence, 10mm Height
LAUNCH BEAM: TSL1
TS
L1
Adjustableheight
DET
Magnetic field
Trap laser
Launch laser
onoff
onoff
onoff
300 ms
3 ms 100 ms
5 ms 100 ms
1 2 3 4 5 6 7 8 9
x 10-3
0
0.1
0.2
0.3
0.4
0.5
Time (sec.)
Det
ecto
r Vol
tage
(V)
REALIZING THE FORT IN-SITU
F'
F
1
2
3
4
2
3
5S1/ 2
5P3/2
780.1 nm
3036
29.3
63.4
120.7
Fig. 2
1 2
3
TS
L1
TSL3IMAGE INTENSIFIEDCCD CAMERA
DET
FIBER
782.1 nm
REALIZING THE FORT IN-SITU
TS
L1
IMAGE INTENSIFIEDCCD CAMERA
DET
FIBER FORT
REALIZING THE FORT IN-SITU
TS
L1
IMAGE INTENSIFIEDCCD CAMERA
DET
FIBER FORT
T
=10 m
sec
REALIZING THE FORT IN-SITU
TS
L1
IMAGE INTENSIFIEDCCD CAMERA
DET
FIBER FORT
T
=20 m
sec
REALIZING THE FORT IN-SITU
T=
20 msec
T
=10 m
sec
REALIZING THE HIGH-Q CAVITY
STABILIZING THE HIGH-Q CAVITY
THE NEW CAVITY : SIDE VIEW
THE NEW CAVITY : TOP VIEW
FORT beam input port
Piezo
Cavity beamoutput port
Cavity mirrorholder
THE NEW CAVITY : INTERNAL DETAILS
OFR FT-51x76
Cavity beam output
FORT beam input
Cavity beaminput
PLAN FOR MAGNETICALLY GUIDED FOUNTAIN FOR QMU
TS
L1
LAUNCH BEAM: TSL1
S-D
L
TS
L2
TSL3F'
F
1
2
3
4
2
3
5S1/ 2
5P3/2
780.1 nm
3036
29.3
63.4
120.7
Fig. 2
1 2
3
810 nm
MagneticallyGuided Fountain
0.7 NA Mic. Objective
DCM
Im. Int. CCD
PUBLICATIONS AND PUBLICITY
“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)
Frequency Stabilization of an Extended Cavity Semiconductor Laser for Chirped Cooling,” J.A. Morzinsky, P.S. Bhatia, and M.S. Shahriar, to appear in Review of Scientific Instruments
“Observation of Ultraslow and Stored Light Pulses in a Solid,” A. V. Turukhin, V.S. Sudarshanam, M.S. Shahriar, J.A. Musser, B.S. Ham, and P.R. Hemmer, Phys. Rev. Lett. 88, 023602 (2002).
“Determination Of The Phase Of An Electromagnetic Field Via Incoherent Detection Of Fluorescence,” M.S. Shahriar, P. Pradhan, and J. Morzinski , submitted to Phys. Rev. Letts. (quant-ph/0205120).
Cavity Dark State for Quantum Computing,” M.S. Shahriar, J. Bowers, S. Lloyd, P.R. Hemmer, and P.S. Bhatia, Opt. Commun. 195, 5-6 (2001
“Physical limits to clock synchronization,” V. Giovannetti, S. Lloyd, L. Maccone, and M.S. Shahriar, Phys. Rev. A 65, 062319 (2002)
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