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 of All 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, (2001)

TELEPORTATION: WHAT EARTH ALPHA-CENTAURI |  |  BEFORE... AFTER... |  | 

BOB ALICE |  |  |  |W  |  |  |  |  BELL STATES |    |    |    |    DECOMPOSITION  |    |     |    |     |    |     |    |    TELEPORTATION: VIA BELL STATE MEASUREMENT

BOB ALICE |  |  |W  |     |     |     |      |     |      |     |    | |       |  | |    0 01 || | |    || | |    0 10 || || || WHERE

NBNB Time |B>|B> |E> |A>|A> LASER-CONTROLLED SPIN EXCITATIONOFF-RESONANT GOOD FOR SINGLE BIT OPERATION

|E> (|A> + |B>)|+>= (|A> - |B>)|->= |B> |E> |A> LASER-CONTROLLED SPIN EXCITATIONRESONANT N E (SS) 0 EXPT. IN Rb TWO-PHOTON DETUNING

|e |a |b  2  1 THE DARK STATE:: GENERAL CASE |e   

|a |b 13 |e |a |b |e |a |b 31 |e |a |b 11 |e |a |b

1 0 AMPLITUDE 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1 22 g AB  0 g 22   g 11 AB  0   COHERENCE TRANSFER VIA CAVITY QED

22 11 0 1 INTENSITY TIME 12 11 22 g ATOM 1 ATOM 2 |a 1 > |b 1 > |e 1 > 11 g |a 2 >|b 2 > |e 2 > 22 g    |a 1 b 2 0> |b 1 a 2 0> 11 g 22 g |b 1 b 2 1> |e 1 b 2 0>|b 1 e 2 0>  2 g  1 g  1  2 ONE CAVITY PHOTON |b 1 b 2 0> NO CAVITY PHOTONS ADIABATIC COHERENCE TRANSFER VIA CAVITY-QED DARK STATE |  |a 1 >  |b 1 >)  |b 2 >  |0> |  |b 1 a 2 0>  |b 1 b 2 0>) = |b 1 >   |a 2 >  |b 2 >)  |0>

ep 22 0 22 0 g 22 g 22 0 11 11 0 g 11 g 11 0   0  1  2  1  2  1  2  1  2 ep ATOM B 22 22   ATOM A 11 11       ATOM B TRANSFERRING TWO BITS INTO A SINGLE ATOM VIA CAVITY QED

TRANSFER PHOTON ENTANGLEMENT TO ATOMIC ENTANGLEMENT

EXPLICIT SCHEME IN 87 RB C 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 }/  2 a b c d  a b c d  a b c d 

en 22 0 22 0 g 22 g 22 0 11 11 0 g 11 g 11 0   0  1  2  1  2  1  2  1  2 en ATOM B 22 22   ATOM A 11 11       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  >={|c 2 >  |b 2 >}/  2, |B  >={|d 2 >  |a 2 >}/  2. |  23 >={|A + >(  |b 3 >+  |a 3 >) + |A - >(  |b 3 >-  |a 3 >) + |B + >(  |b 3 >+  |a 3 >)+ | B - >(-  |b 3 >+  |a 3 >)}/2 AFTER TRANSFER |  1 > = |c> 1 BELL STATES

ROTATE SUPERPOSITION-BASIS BELL STATES INTO PURE-BASIS BELL STATES a b c d  |A + >=|c 2 >+|b 2 > |A - >=|c 2 >-|b 2 > |B + >=|d 2 >+|a 2 > |B - >=|d 2 >-|a 2 >. OLD BELL STATES  pulses a b c d  |a + >=|c 2 > |a - >=|b 2 > |b + >=|d 2 > |b - >=|a 2 >. NEW BELL STATES

MEASURING BELL STATES VIA SEQUENTIAL ELIMINATION

THE QMU FORT Beam Cavity Field Rb Atom

THE MACHINERY Trap diagram TSL1 VALVE OVEN SECTION: HV MAIN CHAMBER: UHV LAUNCH BEAM: TSL1 S-DL TSL2 UPPER CHAMBER: UHV TSL3 3

THE CAVITY AND THE FOUNTAIN Trap diagram Launch laser beam Pulsed Servo Beam Pulsed Probe Beam FORT Beam Copper Block For Vibration Isolation

STABILIZING THE CHIRP Trap diagram DIODE LASER DIFFERENTIATOR MULTIPLIER DELAY PULSE GENERATOR INTEGRATORADDER LASER CONTROLLER BS TO EXPERIMENT ABSORPTION CELL F ' F S 1/2 5P 3/ nm 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 Trap diagram LAUNCH BEAM: TSL1 TSL1 ~2mm Adjustable height AOM 1 AOM 2 AOM 3 To sat. abs. locking To trap Launch beam Timers on/off Magnetic field TSL1 DET

REALIZING THE FOUNTAIN LAUNCH Trap diagram Launch Fluorescence, 2 mm Height LAUNCH BEAM: TSL1 TSL1 Adjustable height DET Magnetic field Trap laser Launch laser on off on off on off 300 ms 3 ms 100 ms 5 ms 100 ms

REALIZING THE FOUNTAIN LAUNCH Trap diagram Launch Fluorescence, 10mm Height LAUNCH BEAM: TSL1 TSL1 Adjustable height DET Magnetic field Trap laser Launch laser on off on off on off 300 ms 3 ms 100 ms 5 ms 100 ms

REALIZING THE FORT IN-SITU Trap diagram 3 TSL1 TSL3 IMAGE INTENSIFIED CCD CAMERA DET FIBER nm

REALIZING THE FORT IN-SITU Trap diagram TSL1 IMAGE INTENSIFIED CCD CAMERA DET FIBER FORT

REALIZING THE FORT IN-SITU Trap diagram TSL1 IMAGE INTENSIFIED CCD CAMERA DET FIBER FORT  T=10 msec

REALIZING THE FORT IN-SITU Trap diagram TSL1 IMAGE INTENSIFIED CCD CAMERA DET FIBER FORT  T=20 msec

REALIZING THE FORT IN-SITU Trap diagram  T=20 msec  T=10 msec

REALIZING THE HIGH-Q CAVITY Trap diagram

STABILIZING THE HIGH-Q CAVITY Trap diagram

THE NEW CAVITY : SIDE VIEW

THE NEW CAVITY : TOP VIEW FORT beam input port Piezo Cavity beam output port Cavity mirror holder

THE NEW CAVITY : INTERNAL DETAILS Cavity beam output FORT beam input Cavity beam input

PLAN FOR MAGNETICALLY GUIDED FOUNTAIN FOR QMU Trap diagram TSL1 LAUNCH BEAM: TSL1 S-DL TSL2 TSL nm Magnetically Guided 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, (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, (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/ ). 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, (2002) New Scientist Nature News Science News Business Week New Scientist Laser Focus World Photonic Spectra EE-Times German Radio Italian Daily Physics News Update