EDM in ground state (I=1/2)
H = -(d E + μ B) · I/I
mI = 1/2
parallel
B
2ω1
anti-parallel
E
B
E
2ω2
mI = -1/2
Electric Dipole Moment:
Precession Frequency:
ω1
ω2
eh
d=
I
2mc
w=d·E/h
d = 10-26 e cm, E = 100 kV/cm,
 w = 15 *10-6 rad/s
Trapped Radioactive Isotopes: micro-laboratories for fundamental Physics
Laser cooling leaky systems: Barium
3D
1
Multiple repump
transitions
1P
1
1D
l1
Efficient capture from
atomic beam (>1%)
2
3D
Rate
[10
6
/s]
1S
3
2
1
Radium similar level
scheme. Laser cooling
approach transferable
0
● MOT signal
150
● Doppler-free beam signal
100
50
X 100
0
-80
-60 -40 -20
0
Detuning @ l1 [MHz]
20
S. De et al., Phys. Rev. A 79 , 041402(R) (2009)
Trapped Radioactive Isotopes: micro-laboratories for fundamental Physics
Intrinsic sensitivity Radium
7s7p 1P1
2
7s6d 1D2
7s7p
3P
1
0
7s6d 3D
3
2
1
EDM Enhancement
over 199Hg
~ 40000
 3D2 | er | 3P1  3P1 | H EDM | 3D2 
d
E ( 3D2 )  E ( 3P1 )
482.7 nm
714.3 nm
Octupole deformation for some
isotopes (225Ra) enhancement
50-500
7s2 1S0
Radium Level Scheme
Trapped Radioactive Isotopes: micro-laboratories for fundamental Physics
225Ra
7s2 1S0
7s7p 1P1
_
Strong transition for efficient laser cooling
7s7p 1P1
7s6d
Hyperfine Structure 4198(4) MHz
7s7p
482.7 nm
F = 1/2 - F = 3/2
2
1D
2
3P
1
0
7s6d 3D
F = 1/2 - F = 3/2
3
2
1
130Te
2
130Te
2
714.3 nm
7s2 1S0
Reference line
in 130Te2 at
20715.4777 cm-1
Trapped Radioactive Isotopes: micro-laboratories for fundamental Physics