Quantum Memory For Teleportation And the Quantum Internet

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, 167903 (2001)

TELEPORTATION: WHAT | > = | > + | > BEFORE. . . | > = | > ALPHA-CENTAURI EARTH AFTER. . . | > = | > + | >

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

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

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

|e 3 |a |e |e |b |a 1 |b 1 |a |e 3 |b |a |b

|e |e |a AMPLITUDE ADIABATIC TRANSFER VIA THE DARK STATE |b |- 1 0 |+ TIME |-> = ( 2|a> - 1|b>)/ |+> = ( 1|a> + 2|b>)/ |a> - |e> EQUIVALENT TO A -PULSE TOPOLGICALLY ROBUST |+> - |e> |->=|b> |a> + |e> |b> - |e> |->=|a> |+> + |e> |b> + |e>

COHERENCE TRANSFER VIA CAVITY QED ATOM A 1 g ATOM B g 2 2 0 0 A B

1 2 g 1 2 ATOM 1 |e 1> 1 |a 1> g |b 1> |a 2> 1 2 1 0 TIME ATOM 2 |e 2> 2 INTENSITY ADIABATIC COHERENCE TRANSFER VIA CAVITY-QED DARK STATE g NO CAVITY PHOTONS 1 |b 1 b 2 0> |b 2> | > = ( |a 1> + |b 1>) |b 2> |0> ONE CAVITY PHOTON |e 1 b 2 0> |b 1 e 2 0> b g g 2 |a 1 b 2 0> |b 1 b 2 1> |b 1 a 2 0> 2 g 1 2 1 g a | > = ( |b 1 a 2 0> + |b 1 b 20>) = |b 1> ( |a 2 > + |b 2>) |0>

TRANSFERRING TWO BITS INTO A SINGLE ATOM VIA CAVITY QED ATOM A ATOM B 1 2 1 1 1 0 ATOM A g g 2 0 0 2 2 2 g g e p 1 2 0 1 2 1 2

TRANSFER PHOTON ENTANGLEMENT TO ATOMIC ENTANGLEMENT

EXPLICIT SCHEME IN 87 RB B C D A

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

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

COMPLETE STATES OF ALL THREE ATOMS 2 3 a b c d 1 | 23>={|a>2|b>3 - |b>2|a>3}/ 2 | 1> ={ |c>1+ |a>1}

TRANSFERRING TWO BITS INTO A SINGLE ATOM VIA CAVITY QED ATOM A ATOM B 1 2 1 1 1 0 ATOM A g g 2 0 0 2 2 2 g g e n 1 2 0 1 2 1 2

TRANSFER STATES OF 1 AND 2 INTO 2 ONLY

QUANTUM STATE AFTER THE TRANSFER BEFORE TRANSFER | 23>={|a>2|b>3 - |b>2|a>3}/ 2 | 1> ={ |c>1+ |a>1} 2 AFTER TRANSFER 3 a b c d 1 | 1> = |c>1 | 23>={|A+>( |b 3>+ |a 3>) + |A->( |b 3>- |a 3>) + |B+>( |b 3>+ |a 3>)+ | B->(- |b 3>+ |a 3>)}/2 BELL STATES |A >={|c 2> |b 2>}/ 2, |B >={|d 2> |a 2>}/ 2.

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

MEASURING BELL STATES VIA SEQUENTIAL ELIMINATION

THE QMU FORT Beam Cavity Field Rb Atom

THE MACHINERY TSL 3 TSL 1 UPPER CHAMBER: UHV VALVE S-DL MAIN CHAMBER: UHV TSL 2 LAUNCH BEAM: TSL 1 OVEN SECTION: HV VALVE 3

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

STABILIZING THE CHIRP ABSORPTION CELL DIFFERENTIATOR BS TO EXPERIMENT MULTIPLIER DIODE LASER DELAY PULSE GENERATOR ' F 4 5 P 3/2 120. 7 3 2 1 ADDER 63. 4 29. 3 INTEGRATOR 780. 1 nm 1 2 LASER CONTROLLER F 3 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 5 S 1/ 2 3036 2

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

REALIZING THE FOUNTAIN LAUNCH Launch Fluorescence, 2 mm Height TSL 1 300 ms Adjustable height DET LAUNCH BEAM: TSL 1 Magnetic field Trap laser Launch laser on off 3 ms 100 ms 5 ms 100 ms on off

REALIZING THE FOUNTAIN LAUNCH Launch Fluorescence, 10 mm Height TSL 1 300 ms Adjustable height DET LAUNCH BEAM: TSL 1 Magnetic field Trap laser Launch laser on off 3 ms 100 ms 5 ms 100 ms on off

REALIZING THE FORT IN-SITU TSL 1 3 2. 1 8 7 IMAGE INTENSIFIED CCD CAMERA nm 3 L S T FIBER DET

REALIZING THE FORT IN-SITU TSL 1 IMAGE INTENSIFIED CCD CAMERA FIBER FORT DET

REALIZING THE FORT IN-SITU DT=10 msec TSL 1 IMAGE INTENSIFIED CCD CAMERA FIBER FORT DET

REALIZING THE FORT IN-SITU DT=20 msec TSL 1 IMAGE INTENSIFIED CCD CAMERA FIBER FORT DET

REALIZING THE FORT IN-SITU DT=20 msec DT=10 msec

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 mirror holder Cavity beam output port

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

PLAN FOR MAGNETICALLY GUIDED FOUNTAIN FOR QMU TSL 1 Im. Int. CCD TSL 3 m 810 n DCM 0. 7 NA Mic. Objective Magnetically Guided Fountain 3 S-DL TSL 2 LAUNCH BEAM: TSL 1

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