Long-lived, Interacting Neutral Atom Quantum Memories

A.  Marchenkova,  Y.  O.  Dudin,  A.  G.  Radnaev,  R.  Zhao,  J.  Z.  Blumoff,  S.  D.  Jenkins,  T.  A.  B.  Kennedy  and  A.  Kuzmich    

 

ACC Meeting of the Minds 2011

Applications Quantum cryptography Quantum computers

Qubits – superposition of states nuclear spin, atoms, photons

Quantum Properties Uncertainty Interference Entanglement Collective matter excitations Neutral atoms Ions

Quantum telecommunication

Long lived quantum memory

Rubidium

spinwave signal

idler

write

read

50 µm – Motional coherence

a b

c

write

signal

read

idler

DLCZ Protocol

795 nm emission

Laser cooling

Differential ac-Stark shift limited lifetime

5 ms

7 ms

Classical and quantum light storage

Storage of coherent light:

07.00.0)ms60( ±=α

12.018.0)s1.0( ±=α

Storage of single photons:

0/0, 1/-1, -1/1 coherences are observed to have similar lifetimes, limited by the 0.5 W power of the 931 nm light

0.12 s (48 µK) 12 ms

0.07 s (62 µK)

0.17 s (33 µK)

Light storage in a 1D optical lattice

Clock coherence

15 ms

0.32 s

Y. O. Dudin et al, PRA 81, 041805 (2010)

efficiency lifetime this work 3.3 % 0.32 s Mott insulator* 0.3 % 0.24 s

Telecom wavelengths

Communication channels

Free space: satellites, ground stations Waveguides: Telecommunication fibers

Nobel prize 2009 / 2 "for groundbreaking achievements concerning the transmission of light in fibers for optical communication“ Charles K. Kao

≤ 2.50 dB/km @ 795 nm ≤ 0.35 dB/km @ 1310 nm ≤ 0.20 dB/km @ 1550 nm

1 mile 8 miles

13 miles

Telecom transitions for quantum memories

•  Alkalis (Rb, Cs, K, Na) T. Chaneliere et al, PRL 96, 093604 (2006)

5S1/2

6S1/2

5P1/2 5P3/2

4D3/2 4D5/2 1324

1367 1475

1529

Rb telecom transitions

There may be potential telecom transitions in other systems (quantum dots, ions,…)

Telecom compatible long-lived quantum memory

Quantum memory entangled with telecom light

memory @ 1ms memory with telecom @ 1 µs

Long-lived quantum memory

Experiment Professor Alex Kuzmich Graduate students: Corey Campbell (Th) Yaroslav Dudin (Rb) Alex Radnaev (Rb, Th) Ran Zhao (Rb) Undergraduate students: Anastasia Marchenkova (Rb) Jacob Blumoff (Rb, Th)

Theory Professor Brian Kennedy Post-docs Francesco Bariani Stewart Jenkins (Southampton) Graduate students: Richard Jen Tingnan Zhang