Quantum Memory For Teleportation And the Quantum Internet

1. 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

2. 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 BASIC OBJECTIVES “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)

3. TELEPORTATION: WHAT BEFORE... |f> = |> |y> = a |> + b |> ALPHA-CENTAURI EARTH AFTER... |f> = a |> + b |> |y> = |>

4. |Y> = ( |> - |> ) /2 TELEPORTATION: VIA BELL STATE MEASUREMENT |F> = a |> + b |> | 2 |W> = a (|> - |>) + b (|> - |>) BELL STATES DECOMPOSITION ALICE |B1> = ( |> - |  > ) /2 |> = (|B4> + |B3>) /2 |B2> = ( |> + |  > ) /2 |> = (|B4> - |B3>) /2 BOB |B3> = ( |> - |  > ) /2 |> = (|B2> + |B1>) /2 | > = (|B2> - |B1>) /2 |B4> = ( |> + |  > ) /2

5. |F> = a |> + b |> |x> |B> | 2 |W> = |B1>|x1> + |B2>|x2>+ |B3>|x3>+ |B4>|x4> WHERE ALICE a | |x1> = - (a |> + b | >) = - = - |F> b -1 0 | |x2> = |F> 0 1 BOB 0 1 | |x3> = |F> 1 0 0 -1 | |x4> = |F> 1 0

6. LASER-CONTROLLED SPIN EXCITATION OFF-RESONANT |E> NB |B> |A> Time GOOD FOR SINGLE BIT OPERATION

7. LASER-CONTROLLED SPIN EXCITATION RESONANT |E> |E> |B> |+>= (|A> + |B>) |A> |->= (|A> - |B>) NE(SS) 0 EXPT. IN Rb TWO-PHOTON DETUNING

8. THE DARK STATE:: GENERAL CASE |e |e W W W 2 1 - |b + |a

9. |e |e |e |e |e 1 1 3 1 1 3 |b |b |b |b |b |a |a |a |a |a

10. ADIABATIC TRANSFERVIA THE DARK STATE |e |e |+> - |e> |a> - |e> |b> - |e> |->=|b> |->=|a> |- |+ |b |a |-> = (2|a> - 1|b>)/ |+> = (1|a> + 2|b>)/ |a> + |e> |b> + |e> |+> + |e> 1 EQUIVALENT TO A -PULSE AMPLITUDE TOPOLGICALLY ROBUST 0 TIME

11. COHERENCE TRANSFER VIA CAVITY QED ATOM A ATOM B g 1 2 1 2 g g   0 0  1 1  A B A B

12. ADIABATIC COHERENCE TRANSFERVIA CAVITY-QED DARK STATE 1 2 1 2 g INTENSITY 1 0 1 2 TIME ONE CAVITY PHOTON NO CAVITY PHOTONS |e1 b2 0> |b1 e2 0> ATOM 1 ATOM 2 |e1> |e2> 2 1 g g 1 2 g g |a1 b2 0> |b1 b2 1> |b1 a2 0> |b1 b2 0> |b1> |a1> |a2> |b2> 2 g 12 1 g a b 0 1 a b |y> = (a |b1 a2 0> + b |b1b20>) = |b1>  (a |a2 > + b |b2>)  |0> |y> = (a |a1> + b |b1>)  |b2>  |0>

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

14. TRANSFER PHOTON ENTANGLEMENT TO ATOMIC ENTANGLEMENT

15. B EXPLICIT SCHEME IN 87RB C D A

16. ATOM 1 IN ARBITRARY STATE: TO BE TELEPORTED 3 2 a a a b b b c c c |1> ={|c>1+|a>1} d d d 1

17. ATOMS 2 AND 3 ARE FIRST ENTANGLED USING THE PHOTON-CAPTURE PROCESS ATOM 2 ATOM 3 a a b b c c d d |23>={ |a>2|b>3- |b>2|a>3}/2

18. COMPLETE STATES OF ALL THREE ATOMS 3 2 a a a b b b c c c |1> ={|c>1+|a>1} d d d |23>={|a>2|b>3 - |b>2|a>3}/2 1

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

20. TRANSFER STATES OF1 AND 2INTO2 ONLY

21. QUANTUM STATE AFTER THE TRANSFER BEFORE TRANSFER |23>={|a>2|b>3 - |b>2|a>3}/2 |1> ={|c>1+|a>1} AFTER TRANSFER 3 2 |1> = |c>1 a a a b b b |23>={|A+>(|b3>+|a3>) + |A->(|b3>-|a3>) + |B+>(|b3>+|a3>)+ | B->(-|b3>+|a3>)}/2 c c c d d d BELL STATES |A>={|c2>|b2>}/2, |B>={|d2>|a2>}/2. 1

22. ROTATE SUPERPOSITION-BASIS BELL STATES INTO PURE-BASIS BELL STATES p/2 pulses 2 2 a a b b OLD BELL STATES NEW BELL STATES c c d d |A+>=|c2>+|b2> |A->=|c2>-|b2> |B+>=|d2>+|a2> |B->=|d2>-|a2>. |a+>=|c2> |a->=|b2> |b+>=|d2> |b->=|a2>.

23. MEASURING BELL STATES VIA SEQUENTIAL ELIMINATION

24. FORT Beam Cavity Field Rb Atom THE QMU

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

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

27. Trap diagram ' F 4 5 P 120.7 3 / 2 3 63.4 2 29.3 1 1 2 780.1 nm F 3 3036 5 S 1 / 2 2 STABILIZING THE CHIRP ABSORPTION DIFFERENTIATOR CELL BS TO DELAY EXPERIMENT PULSE MULTIPLIER GENERATOR DIODE LASER ADDER INTEGRATOR LASER CONTROLLER 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

28. Trap diagram TSL1 TSL1 To sat. abs. locking AOM 1 AOM 2 Timers To trap on/off AOM 3 on/off ~2mm Launch beam Adjustable height on/off Magnetic field DET LAUNCH BEAM: TSL1 REALIZING THE FOUNTAIN LAUNCH

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

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

31. Trap diagram TSL1 3 782.1 nm TSL3 IMAGE INTENSIFIED CCD CAMERA FIBER DET REALIZING THE FORTIN-SITU

32. Trap diagram REALIZING THE FORTIN-SITU TSL1 IMAGE INTENSIFIED CCD CAMERA FIBER FORT DET

33. Trap diagram DT=10 msec REALIZING THE FORTIN-SITU TSL1 IMAGE INTENSIFIED CCD CAMERA FIBER FORT DET

34. Trap diagram TSL1 DT=20 msec IMAGE INTENSIFIED CCD CAMERA FIBER FORT DET REALIZING THE FORTIN-SITU

35. Trap diagram DT=20 msec DT=10 msec REALIZING THE FORTIN-SITU

36. Trap diagram REALIZING THE HIGH-Q CAVITY

37. Trap diagram STABILIZING THE HIGH-Q CAVITY

38. THE NEW CAVITY : SIDE VIEW

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

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

41. Trap diagram PLAN FOR MAGNETICALLY GUIDED FOUNTAIN FOR QMU Im. Int. CCD TSL1 TSL3 810 nm DCM 0.7 NA Mic. Objective Magnetically Guided Fountain 3 S-DL TSL2 LAUNCH BEAM: TSL1

42. 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) • Nature News • Science News • Business Week • New Scientist • Laser Focus World • Photonic Spectra • EE-Times • German Radio • Italian Daily • Physics News Update New Scientist