Orologi e interferometri atomici
nuovi sensori ad atomi ultrafreddi
per esperimenti di fisica fondamentale e applicazioni
in laboratori terrestri e nello spazio
Guglielmo M. Tino
Dipartimento di Fisica, LENS - Università degli Studi di Firenze
INFN, Sezione di Firenze
G.M. Tino, LNF, 16/2/2005
Laser cooling of atoms
nL
v
nL
Lab ref. frame
nL(1-v/c)
Idea:
T.W. Hänsch, A. Schawlow, 1975
Exp. demonstration:
S. Chu et al., 1985
nL(1+v/c)
Atom ref. frame
Sr MOT
LENS, Firenze
2 8
I / I v = - v
h

F (v)
4 2 c2  [1 (2 )2]2
L
0
G.M. Tino, LNF, 16/2/2005
The Nobel Prize in Physics 1997
G.M. Tino, LNF, 16/2/2005
The Nobel Prize in Physics 2001
G.M. Tino, LNF, 16/2/2005
Atom optics
Oven
Atomic beam
lenses
Atom Laser
atom
mirrors
atom
beam-splitters
interferometers
laser
2 mm
laser
T>Tc
T<Tc
G.M. Tino, LNF, 16/2/2005
m-traps
Laser Cooling and loading: (<10 s)
Single MOT system (need <50 mW of light)
108 atoms at T  50 mK and n  1010 cm-3
Evaporative cooling: (<1 s)
Static magnetic trap (Ioffe-type)
(need < 10 W)
 105 atoms in condensate
na = 1 kHz
nr = 10 kHz
BEC production time < 10 s
G.M. Tino, LNF, 16/2/2005
Atomic clocks
The definition of the second
Dn.Dt = 1
The second is the duration of
9 192 631 770 periods of the
radiation corresponding to the
transition between the two
hyperfine levels of the ground
state of the 133Cs atom
(13th CGPM, 1967)
G.M. Tino, LNF, 16/2/2005
Atomic clocks
•
•
•
•
•
Location finding
Precision navigation and navigation in outer space
Variability of Earth’s rotation rate and other periodic phenomena
Earth’s crustal dynamics
Secure telecommunications
•
•
•
•
•
Very Long Baseline Interferometry (VLBI)
Spectroscopy
Expression of other physical quantities in terms of time
Tests of constancy of fundamental constants
Tests of the special and general theories of relativity
G.M. Tino, LNF, 16/2/2005
Accuracy of the atomic time
ACCURACY OF THE ATOMIC TIME
RELATIVE ACCURACY
1x10
-9
1x10
-10
1x10
-11
1x10
-12
1x10
-13
1x10
-14
10
-15
1x10
-16
10
-17
1950
Microwave clocks
Slope: gain of 10 every 10 years
Optical clocks
NPL
NBS
LSRH
Ca PTB
PTB
NRC
NBS
VNIIFTRI
H MPQ
PTB
NIST
NPL
PTB NIST
SYRTE
Cold atoms
1960
1970
1980
1990
2000
?
2010
YEAR
from C. Salomon
G.M. Tino, LNF, 16/2/2005
Towards a Sr clock – The experiment in Firenze
Firenze 2003, Magneto-optical trapping of all Sr isotopes
• Optical clocks using visible
intercombination lines
0.20
86
88
Sr
0.18
87
Sr
Sr
88
Sr
Sr
87
Sr
Fluorescence signal (V)
0.16
0.14
86
0.12
0.10
84
0.08
Sr
0.06
84
0.04
-400
-200
0
200
Sr
Abundance
82.6%
9.9%
7.0%
1S
0
1S
0
1S
0
- 3P1 (7.5 kHz)
- 3P0 (1 mHz, 87Sr)
- 3P2 (0.15 mHz)
Optical trapping in Lamb-Dicke regime
with negligible change of clock frequency
Comparison with different ultra-stable clocks
(PHARAO/ACES)
PHARAO
0.6%
Laser detuning (MHz)
Isotope
88
Sr
87
Sr
I
0
9/2
transition
1
S0-3P1
1
S0-3P0
lifetime
20 ms
200 s

689 nm
698 nm
tint
10 ms
0.5 s
y t-1/2
2 10-13
10-17
abundance
83%
7%
http://www.lens.unifi.it/poli/
G.M. Tino, LNF, 16/2/2005
Atomic Clock Ensemble in Space
H= 400 km
V=7 km/s
T= 5400 s
• A cold atom clock in space
• Worldwide access
• Fundamental physics tests
PHARAO : Cold Atom Clock in Space. CNES (France)
A. Clairon, P. Laurent, P. Lemonde, M. Abgrall, S. Zhang, C. Mandache, F.
Allard, M. Maximovic, F. Pereira, G. Santarelli, Y. Sortais, S. Bize, H.
Marion, D. Calonico, (BNM-LPTF), N. Dimarcq (LHA), C. Salomon (ENS)
SHM : Space Hydrogen Maser. ON (Switzerland)
L. Jornod, D. Goujon, L.G. Bernier, P. Thomann, G. Busca
MWL : Microwave link. Kayser-Threde-Timetech (Germany)
W. Schaefer, S. Bedrich
ACES is open to any interested scientific user
W. Knabe, P. Wolf, L. Blanchet, P. Teyssandier, P. Uhrich, A. Spallici
New members :
2001: UWA (Australia), A. Luiten, M. Tobar, J. Hartnett, R. Kovacich
2002: LENS (Italy), G.M. Tino, G. Ferrari, L. Cacciapuoti
ESA: MSM
Stephen Feltham
CNES:
C. Sirmain + team of 20 engineers at CST, Toulouse
Support: ESA, CNES, BNM, CNRS
G.M. Tino, LNF, 16/2/2005
ACES ON COLUMBUS EXTERNAL
PLATFORM
ACES
M = 227 kg
P = 450 W
Launch date : end of 2008
Mission duration : 18 months
G.M. Tino, LNF, 16/2/2005
ACES objectives
L. Blanchet, C. Salomon, P. Teyssandier, and P. Wolf, A&A 370, 320 (2001)
G.M. Tino, LNF, 16/2/2005
PARCS
Primary Atomic Reference Clock in Space
G.M. Tino, LNF, 16/2/2005
Atom Interferometry
Atom interferometer
Flux
D
Phase difference
D  1  2
atomic flux at exit port 1
at exit port 2
G.M. Tino, LNF, 16/2/2005
Matter wave sensors
accelerations:
D acc  k T
2
drift
a
2
a
rotations:

D mat  c 
~    1011  1017
D ph  v at 
2 mat
D rot  2
A 
h
D mat m at    c
10
~
 5  10
D ph
h
G.M. Tino, LNF, 16/2/2005
Atom gravimeter/gradiometer in Firenze
 Dg g  8.6  106
1
 9.1  107 in 90 s
Hz
G.M. Tino, LNF, 16/2/2005
MAGIA
Misura Accurata di G mediante Interferometria Atomica
I
II
z1
1
1
z2
2
2
In collaboration with LNF, Frascati
http://www.fi.infn.it/sezione/esperimenti/MAGIA/home.html
G.M. Tino, LNF, 16/2/2005
HYPER
Mapping Lense-Thirring
effect close to the Earth

Improving knowledge of
fine-structure constant
Differential measurement between
two atom gyroscopes and a star
tracker orbiting around the Earth
D~h/m
Testing EP with
microscopic bodies
Atomic gyroscope
control of a satellite
G.M. Tino, LNF, 16/2/2005
Laser Cooled Atom (LCA) Sensor
for Ultra-High-Accuracy Gravitational Acceleration
and Rotation Measurements
in response to ESA ITT No. AO-1-4477/03/NL/CH
G.M. Tino, LNF, 16/2/2005
ICE : interferometry in 0-g
G.M. Tino, LNF, 16/2/2005
G.M. Tino, LNF, 16/2/2005
G.M. Tino, LNF, 16/2/2005
Future prospects:
Atom interferometers
• Development of transportable
atom interferometers
geophysics
space
EC-STREP “FINAQS”: BEC or Fermionic Source?
• Test of Newton’s law at short distances
• Test of equivalence principle
• New definition of kg
• Accurate measurement of h/m and 
• Search for electron-proton charge inequality
• Test of equivalence principle for anti-matter (?)
• New detectors for gravitational waves (?)
G.M. Tino, LNF, 16/2/2005
Gravitational wave detection by atom interferometry
Presentation at 2004 Aspen Winter College on Gravitational Waves:
See http://www.ligo.caltech.edu/LIGO_web/Aspen2004/pdf/vetrano.pdf
See also:
Chiao RY, Speliotopoulos AD, J. Mod. Opt. 51, 861 (2004)
A. Roura, D.R. Brill, B.L. Hu, C.W. Misner, gr-qc/0409002
G.M. Tino, LNF, 16/2/2005
Fine
G.M. Tino, LNF, 16/2/2005