Post on 04-Feb-2016
description
Fast and RobustLaser Cooling of
Trapped SystemsJavier Cerrillo-Moreno, Alex Retzker, Martin B.
Plenio
Obergurgl, 7th June 2010
2
Motivation
Quantum Information ProcessingQuantum SimulationQuantum OpticsLocalized quantum objectPrecision measurementsSpectroscopy
R. Blatt
3
Overview
Cooling schemes for trapped systems
Building BlocksEIT coolingStark-shift cooling
ProposalConceptMechanismFeatures
4
One-phonon processesCarrier transitionBlue side-band transitionRed side-band transition
1
2
g
e 1
0
2
0
neng
1 neng
1 neng
g
e
g
e
g
e
€
1
€
0€
2
€
3
€
4
€
5
€
⊗
5
Side-band cooling
1
2
g
e 1
0
2
0g
e
g
e
Carrier TransitionBlue side-band transitionRed side-band transition
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Dark-state cooling
1
2
g
e 1
0
2
0g
e
g
e
Carrier TransitionBlue side-band transitionRed side-band transition
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Dark-state cooling
1
2
g
e 1
0
2
0g
e
g
e
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Double Dark-state cooling ?
1
2
g
e 1
0
2
0g
e
g
e
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Overview
Cooling schemes for trapped systems
Building BlocksEIT coolingStark-shift cooling
ProposalConceptMechanismFeatures
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Electromagnetically-Induced Transparency EIT cooling
22
e
}
Ω, -ηΩ, η
Morigi, Eschner and Keitel PRL, 85 (2004)
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Stark Shift cooling
2
c
e
}
ΩΩ
Ωc, η
1 nn
1n n 1n
ν
Stark Shift gate
A. Retzker, M. Plenio, New J. of Phys. 9 (2007) 279
€
− =↑ −↓
+ =↑ + ↓
Cooling schemes for trapped systems
Building BlocksEIT coolingStark-shift cooling
ProposalConceptMechanismFeatures
12
Overview
J. Cerrillo, A. Retzker, M. Plenio, Phys. Rev. Lett. 104,
043003 (2010)
13
Robust cooling – Concept
e
}
ΩaΩa
Ωb, ηb
e
}
Ωa, -ηaΩa, ηa
Ωb, ηb
J. Cerrillo, A. Retzker, M. Plenio, Phys. Rev. Lett. 104, 043003 (2010)
14
Robust cooling – Steady state
Stark Shift OREIT cooling
Stark Shift ANDEIT cooling €
ρss = ↓ −↑ ↓ −↑ ⊗ an
n
∑ n n ⎛
⎝ ⎜
⎞
⎠ ⎟+ o(η 2)
€
Ψss
= ↓ −↑ 0 + o(η ) )(00 2ρ oss
€
Ψss
= ↓ −↑ 0 − iη ↓ +↑ 1 + o(η 2)
η b
η a
=ν + 2Ωb
Ωb
e
}
Ωa, -ηaΩa, ηa
Ωb, ηb
J. Cerrillo, A. Retzker, M. Plenio, Phys. Rev. Lett. 104, 043003 (2010)
€
∂∂t
ρ = Lρ = −i H,ρ[ ] +Γ
2˜ L ρ = 0
15
Robust cooling – Mechanism
e
e
e
e
e
1 2 3 40
HEIT
Hint = HEIT + HSS = 0 + a
ssΨ
ssΨ
ssΨ
ssΨHEIT
= 0ss
Ψ
HEIT
HEITHEIT
HSS ≠ a
ssΨ
ssΨ
J. Cerrillo, A. Retzker, M. Plenio, Phys. Rev. Lett. 104, 043003 (2010)
16
Robust cooling – Features
)(0 2on
2
2
W
e
}
Ωa, -ηaΩa, ηa
Ωb, ηb
J. Cerrillo, A. Retzker, M. Plenio, Phys. Rev. Lett. 104, 043003 (2010)
Final Temperature
Cooling rate
€
b
η a
=ν + 2Ωb
ΩbImplementation
Robust cooling - Implementation
17
e
}
Ωa, -ηaΩa, ηa
Ωb, ηb
€
b
η a
=ν + 2Ωb
Ωb
=2η p
η 'A cosθ=
2
cosθ
J. Cerrillo, A. Retzker, M. Plenio, Phys. Rev. Lett. 104, 043003 (2010)
18
Robust cooling – Features
)(0 2on
€
n ∝ ΔΩb( )4
ΔΩa( )4
2
2
W
e
}
Ωa, -ηaΩa, ηa
Ωb, ηb
J. Cerrillo, A. Retzker, M. Plenio, Phys. Rev. Lett. 104, 043003 (2010)
Final Temperature
Cooling rate
Robustness
€
b
η a
=ν + 2Ωb
ΩbImplementation
19
Robust cooling – Robustness
e
}
Ωa, -ηaΩa, ηa
Ωb, ηb
J. Cerrillo, A. Retzker, M. Plenio, Phys. Rev. Lett. 104, 043003 (2010)
20
Summary
Interference of 2 cooling schemes
Steady state is a pure state
Best final T and cooling rate
Easy implementation
Experimentally robust
€
Ψss
= − 0 − iη + 1 + o(η 2)
)(0 2on
e
e
10
2
2
W
e
}
Ωa, -ηaΩa, ηa
Ωb, ηb
J. Cerrillo, A. Retzker, M. Plenio, Phys. Rev. Lett. 104, 043003 (2010)