Optimal Pulse sequences for efficient population
transfer in lower (n<10) Rydberg states
Mudessar ShahHow Camp
Marc Trachy
Supervisor:Brett DePaola
Application
Need for a system to be in a specified quantum state
o Laser control of chemical reactions
o Atom optics
o Quantum information
0.0
0.5
1.0
Exc
i. p
opu
lati
on
time
incoh. exc.
coh. exc.adiab.
Two level system
k Absorp.
E=ћωP=ћKJ= ћ
E=0P=0J= 0
E=ћωP=ћKJ= ћ
Pe(t)=1/2[1-e-F(T)]F(T)= I(t)dt
Pe(t)=1/2[1-cosΩt]
when radiation varies in amplitude cosine argument is
replaced by so-called pulse area
Advantages
Excitation between state of same parity can be produced, for which single photon transition are forbidden for electric dipole radiation, or between magnetic sublevels. (for 3 and higher)
Excitation efficiency can be made insensitive to many of experimental details (pulse area, Shape etc).
100% population transfer between same parity state is possible
-50 0 50 100 150 200
0.0
0.2
0.4
0.6
0.8
1.0
-50 0 50 100 150 200
0
2
4
6
8
10
12 |1> |2> |3>
Po
pu
latio
n
Time (ns)
1,2
(GH
z)
I1 = 250 mW/cm2
w1 = 33 ns
I2 = 250 mW/cm2
w2 = 33 ns
t = 20 ns = 44 MHz
1
2
Theoratical prediction For three level systems
|1>
2
|3>
Ladder
|2>
1
4d
5p
5s
Adiabatic population transfer using sequential pulses (Three photon transition)
Delay1Delay2
L3 L1L2
|4>3
Ladder
|2>
|1>
1
|3>
2
1
2
5s
5p
4d
9f
Q-Value SpectraQ-Value Spectra
50 75 100 125 150
0
500
1000
1500
2000
2500
3000
3500
Co
un
ts
Q-Value (Channel)
5s-3p
4d-3d5s-3s
-5
-4
-3
-2
-1
0
4d 2D5/2
, 4d2D3/2
4f 2F7/2
, 4f2F5/2
4s 2S1/2
4p 2P1/2
, 4p 2P3/2
23Na
4s 2S1/2
3d 2D5/2
, 3d2D3/2
3p 2P
1/2, 3p
2P
3/2
3s 2S
1/2
12f
4d 2D3/2,5/2
5p 2P
3/2
5s 2S
1/2
87Rb
Pote
ntia
l Ene
rgy
(eV)
2D Spectrum2D Spectrum
Q-Value (Channel)
Tim
e (s
)
50 100 150
0.5
1.0
1.5
2.0
2.5
0.0
5s-3p 5p-3p 5s-3s
4d-3d4d-3s
5p-3p
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