QUANTUM MEMORY FOR STORAGE, BELL STATE MEASUREMENTS… · QUANTUM MEMORY FOR STORAGE, BELL STATE...
Transcript of QUANTUM MEMORY FOR STORAGE, BELL STATE MEASUREMENTS… · QUANTUM MEMORY FOR STORAGE, BELL STATE...
QUANTUM MEMORY FOR STORAGE, BELL STATE MEASUREMENTS, AND TELEPORTATION
SELIM SHAHRIAR, NWU
VISITOR: • Dr. Philip Hemmer
• Dr. Venkatesh Gopal• Dr. Gaur Pati• Dr. George Cardoso• Dr. Prabhakar Pradhan
POST-DOCS: • Ken Salit• Jacob Morzinski• Alex Heifetz• Joseph Vornhem
GRAD STUDENTS:
BASIC OBJECTIVES
Demonstrate A Quantum Memory Unit (QMU) In the Form of a Single RbAtom Trapped Inside a High Finesse Cavity
Demonstrate Transfer of Photon Entanglement to a Pair Of QMU’s.
Demonstrate Quantum Teleportation via Measurement of All the Bell States
FORT Beam
Cavity FieldRb Atom
FORT Beam
Cavity FieldRb Atom
THE BASIC MACHINERY
F'
F
5S1/ 2
5P3/2
780.1 nm
3036
29.363.4
120.7
1 2
3
TSL1
VALVE
VALVEO
VEN
SECTIO
N: H
V
MAIN CHAMBER: UHV
FOUNTAIN LAUNCH BEAM: TSL1
S-DL
HP-D
L
UPPER CHAMBER: UHV
TSL3
FOCUSED GUIDE BEAM: TSL3
THE CAVITY AND THE FOUNTAIN
Launch Plus Guide Beams
Pulsed ServoBeam
Pulsed Probe Beam
FORTBeam
Copper Block For Vibration Isolation
THE NEW INTEGRATED CAVITY-FORT: TOP VIEW
FORT beam input port
Piezo
Cavity beamoutput port
Cavity mirrorholder
THE NEW INTEGRATED CAVITY-FORT: DETAILS
OFR FT-51x76
Cavity beam output
FORT beam input
Cavity beaminput
THE FOUNTAIN LAUNCH: NEW AND IMPROVED
AOM 1
AOM 2
AOM 3
To sat. abs.locking
To trap
Launch beam
Timers
on/off
on/off
on/off
Magneticfield
TSL1
LAUNCH BEAM: TSL1
TSL1
~2mmAdjustable
heightDET
THE OLD FORT: IN-SITU
F'
F
5S1/ 2
5P3/2
780.1 nm
3036
29.363.4
120.7
1 2
3
TSL1
TSL3IMAGE INTENSIFIEDCCD CAMERA
DET
FIBER
782.1 nm
ATTEMPT AT GUIDED LAUNCH AND CATCH
LAUNCH WITHOUT GUIDE LAUNCH WITH GUIDE
Precool Atoms Further (e.g., Evaporative Cooling)ALTERNATIVE APPROACHES :
Reduce the Distance Between Cavity and MOT: New ChamberHollow PBG Fiber Plus CO2 Laser Guide For Horizontal Transport
Quadrupolar (Four-Wire) Magnetic Guide and Reduced Distance:Old Chamber Modified
TESTING ATOM-CAVITY COUPLING WITH AN ATOMIC BEAM
CAVITY 1
CAVITY 2UPSIDE-DOWN ATOMIC BEAM
MO
T C
HA
MB
ER
CA
VIT
Y T
RA
NSM
ISSI
ON
LASER DETUNING
CA
VIT
Y T
RA
NSM
ISSI
ON
LASER DETUNING
QUADRUPOLAR MAGNETIC GUIDE, INVERTED CAVITY, REDUCED DISTANCE
FORT
MOT
LAUNCH
QMG
THIS WHOLESTRUCTURE IS IN PLACE IN THEORIGINAL CHAMBER
INVERTED CAVITY, VERY CLOSE TO MOT (NO GUIDE)
FORT
MOT
LAUNCH
THIS WHOLESTRUCTURE IS ALSO IN PLACEIN A NEW CHAMBER
BOTH CHAMBERS OPERATING SIDE-BY-SIDE
FORT
MOT
LAUNCH
QMG
FORT
MOT
LAUNCH
QMGFORT
MOT
LAUNCH
FORT
MOT
LAUNCH
MOT
LAUNCH
DEMONSTRATING THE MECHANISM FOR CAPTURING ENTANGLED PHOTON-PAIR AND MEASURING BELL STATES USING AN ATOMIC BEAM
CAPTURING A PAIR OFENTANGLED PHOTONS
MEASURING THE BELL STATES
THE BASIC APPRATUS BASED ON AN EFFUSIVE ATOMIC BEAM
Fluorescence
Imaging lens
Atomic beam
APD
Probe beam circ. pol.0.35 mmhole
Rb
Oven300 oC
1 mmhole
Liquid N2 cooled rod.
Nozzle380 oC Collimator Fluorescence
Imaging lens
Atomic beam
APD
Probe beam circ. pol.0.35 mmhole
Rb
Oven300 oC
1 mmhole
Liquid N2 cooled rod.
Nozzle380 oC Collimator Fluorescence
Imaging lens
Atomic beam
APD
Probe beam circ. pol.0.35 mmhole
Rb
Oven300 oC
1 mmhole
Liquid N2 cooled rod.
Nozzle380 oC Collimator
Fluorescence
Imaging lens
Atomic beam
APD
Probe beam circ. pol.
0.35 mmhole
Rb
Oven300 oC
1 mmhole
Liquid N2 cooled rod.
Nozzle380 oC Collimator
72 MHz
F=2F =3
F =0
F=1
F=15P1/2
5S1/2 F=2
157 MHz
267 MHz
6835 MHz
STEP-ONE: STATE PREPARATION USING PI-POLARIZED OPTICAL PUMPING
F =0
F=1
F=15P1/2
5S1/2 F=2
Fluorescence
Imaging lens
Atomic beam
APD
Probe beam circ. pol.0.35 mmhole
Rb
Oven300 oC
1 mmhole
Liquid N2 cooled rod.
Nozzle380 oC Collimator
72 MHz
F=1
5P1/2
5S1/2 F=2
F =0
F=1
F=15P1/2
5S1/2 F=2
157 MHz
6835 MHz
100 MHz
Lin σ+ +σ-
STEP-TWO: CAPTURING GREEN PHOTON PAIR INTO ZEEMAN COHERENCE
Fluorescence
Imaging lens
Atomic beam
APD
Probe beam circ. pol.0.35 mmhole
Rb
Oven300 oC
1 mmhole
Liquid N2 cooled rod.
Nozzle380 oC Collimator
72 MHz
F=1
5P1/2
5S1/2 F=2
F =0
F=1
F=15P1/2
5S1/2 F=2
157 MHz
6835 MHz
100 MHz
Lin σ+ +σ-
STEP-THREE: EMITTING GREEN PHOTON PAIR FROM ZEEMAN COHERENCE
Sat abs locked on theF=1 F’= 1
AOM + 2x160 MHz
s+, s- Raman zone 2s+, s- Raman zone 3
p zone 1 (opt. Pump),Cir pol zone 4 (probe)
AOM - 2x1610 MHz
AOM - 2x1610 MHz
p Raman zone 2
p Raman zone 3
AOM +100 MHz
p zone 1 (opt. Pump),
Ti-Sapph Laser
GENERATING THE OPTICAL BEAMS FOR ALL THE OPERATIONS
OBSERVATION OF PHASE-LOCKED BLOCH-SIEGERT OSC.
0.35 mmhole
Rb
Oven
1 mmhole~1 mm~1 mm
Liquid N2 cooled rod.
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
5P3/2 , F’=0
5S1/2 , F=1∆z1
∆z2
∆z2
∆z2
PUMP
Probe
72.3 MHz
5P3/2 , F’=1
5P3/2 , F’=0
5S1/2 , F=1∆z1
∆z2
∆z2
∆z2
PUMP
Probe
72.3 MHz
5P3/2 , F’=1
5P3/2 , F’=0
5S1/2 , F=1∆z1
∆z2
∆z2
∆z2
PUMP
Probe
72.3 MHz
5P3/2 , F’=1
OBSERVATION OF PHASE-LOCKED BLOCH-SIEGERT OSC.
RF generator Power amplifier Coil, Atomic beam and laser
APD
Low noise pre-amplifiers (~ + 25 dB)
Amplifier
Frequency doubler
SCOPE
ESA
Fluorescence
Channel A
Channel B
DIRECT BSO OBSERVED
BSO
SPEC
TR
UM
OB
SER
VE
D
0.0 1.0 2.0 3.0 4.0
Atom
ic F
luor
esce
nce
(arb
. uni
ts) (b)(a)
0.79T
Time (µs)0 2 4 6 8 10
Atom
ic F
luor
esce
nce
(arb
. uni
ts)
Time (µs)
DIRECT PHASE MEASUREMENT
5P3/2 , F’=0
5S1/2 , F=1∆z1
∆z2
∆z2
∆z2
PUMP
Probe
72.3 MHz
5P3/2 , F’=1
5P3/2 , F’=0
5S1/2 , F=1∆z1
∆z2
∆z2
∆z2
PUMP
Probe
72.3 MHz
5P3/2 , F’=1
5P3/2 , F’=0
5S1/2 , F=1∆z1
∆z2
∆z2
∆z2
PUMP
Probe
72.3 MHz
5P3/2 , F’=1
PROGRESS AND OUTLOOK
Demonstrated launching and catchingDesigned and constructed two integrated cavity-FORT systems
Designed, made, and installed a quadrupolar magnetic guide
Constructed an atomic beam and realized the optical frequencies for testing the Mechanisms behind capturing entangled photons and measuring Bell states. Used this beam to observe a process that can be used for phase teleportation.
Created two separate trap chambers, each with a cavity, and one with a magnetic guide.Cavities in each is close to the MOT, within range of launch and catch
PROGRESS SINCE LAST REVIEW
Established that optical guiding does not work well enough
Catch a single atom in each cavity-FORT systemDemonstrate the entanglement-capturing and Bell-state measuring mechanisms usingthe atomic beam
Attempt generation of distribruted entanglement by capturing a pair of entangled Photons, one in each cavity-FORT system
OUTLOOK BY SUMMER 2004
Demonstrate intracavity teleportation via sequential loading of two atoms in the same cavity , without requiring a source of entangled photons