strongly-correlated fermions in optical lattices - apparatus · 2020. 7. 15. · pc pid setpoint pd...
TRANSCRIPT
Apparatus and sequence overview
Interferometer setup for superlattice
Ultracold 40K and 87Rb Optical lattice with tuneable geometry
Team members 2001-2016
AOM
+ c,X+ ref
Coherent Mephisto MOPA 36 NE
Nd:YAG 1064 nm
optical isolator
beam dump
thin filmpolarizer
AOM AOM AOM
+ c,Z + c,X
double AR plate
interference phase PD
AOM
+ c,Y
30:70 plate
mirror
50:50 plate
fiberx axis
fiber y axis
fiber z axis
/2 plate
x and y axis
/4
lattice y
imaging x imaging y
achromatf=400 mm
f=400 mm
Gradiumf=100 mm
f=100 mm
intensity Y
intensity
intensity
anamorphicprism pair
fiberoutcoupler
lattice x
deconf. x
intensityX and X
x
yz
XYX
f=400 mm
FORT x
f=400 mm
f=400 mm
f=400 mm
CC
D
CCD
cleaning plate
RF source p,XPhaseTag X
RF source c,XCarrier X
RF source r,XReference X
AOM driver
AOM X
RF source p,YPhaseTag Y
RF source c,YCarrier Y
RF source r,YReference Y
>> +90dB
FM in
Y monitor DC
Y monitor RF
feedback signal
AOM driver
AOM Y
<< +30dB
c,Y
c,Y
p,Y
p,Y
PC
<< +30dB
>> +90dB
FM in
X monitor DC
X monitor RF
RF source mixMixing down
feed
back
si
gnal
GPS 10 MHz
c,X
c,X
p,X
p,X
PD
Phase stabilization X Phase stabilization Y
PC
delayline
Lase
r In
tens
ity
fixed intensityvariable intensity
Laser frequency
c,X
p,X
p,X
c,Y
p,Y
p,Y
beat X
beat Y
ref
a bX beam
Y beam110 112 114 116 118
PD beat frequency (MHz)
-90-80-70-60-50-40-30-20-10
0
sign
alpow
er(d
Bm
)
beat X
beat Y
RF source i,XIntensityTag X
RF source c,XCarrier X
AOM driver
AOM X
AM in
0 1 2 3 4 5
beat frequency (MHz)
-80
-60
-40
-20
0
20
sign
alpow
er(d
Bm
)
<< +30dB
DC
PIDPCsetpoint
PD>>
a b
beat X intensitybeat X intensity
Intensity stabilisation
Beat notes on photodiodePhase lock: RF electronicsSuperlattice: optical setup on laser table Optical setup on experiment table
(old naming convention)
(old naming convention)
Experiment Theory
~ 0
~ /2
1.20
1.05
0.90
0.75
0.60
0.45
0.30
0.15
0.00
Density (a.u.)
2 k�
Superlattice phase calibration
Raman-Nath/Kapitza-Dirac diffraction on 87Rb BEC
Bx
x y
MOT QUIC FORT
Sympathetic cooling of 40K with 87Rb in QUIC
0 9 19 23time (s)
40K
N 4 106
N 1 109
N 2 106
N=0
87Rb
2 mm
Magnetic coils setup
3
Cloud position
Quadrupole coils
Ioffe
coi
l
Gra
dien
t coi
l
Transportcoils
Glasscell
Scale 1:2
4
18
52.5 59.5
4.1
x
z
y
Fesh
bach
coi
ls
0 50 100 150Position x (px)
0.0
0.5
1.0
OD
(a.u
.)
0.0 0.5 1.0OD (a.u.)
0
50
100
150
Posi
tion
z(p
x)
100 m
xz
400k 40K
0.078 T/TF
21 nK
6.5 6.6 6.7 6.8rf endpoint (MHz)
1.0
1.2
1.4
1.6
1.8
2.0N
K(1
06)
0
1
2
3
NRb
(106
)6.5 6.6 6.7 6.8
rf endpoint (MHz)
0.3
0.4
0.5
T K(T
F)
100
150
200
250
T Rb
(nK)
(a) (b)
Degenerate Fermi gas
Magnetic gradient for K-Rb mixture in FORT
(Quadrupole-Ioffe configuration) (Far-offresonant trap = dipole trap)
θ =
ϕ =
x
z
x
z
x
z
X
ZX
Cubic Hexagonal
Checkerboard Dimers
a
b
c
xy
z
BA
BA
Optical lattice: 1D bandstructure
-1 0 10
5
10
15
-1 0 1 -1 0 1 -1 0 1Quasimomentum q/klat
Ener
gy/E
rec
V0 = 0Erec 2 Erec 20 Erec6 Erec
kx
ky
x
y
Brillouin zone kL=4unit cell
kLA Ba
a1
2D unit cell and Brillouin zone
Potential symmetry phase
superlattice phase
Thilo Stöferle, Henning Moritz, Michael Köhl, Christian Schori, Kenneth Günter, Niels Strohmaier, Robert Jördens, Leticia Tarruell, Daniel Greif, Thomas Uehlinger, Gregor Jotzu, Michael Messer, Rémi Desbuquois, Frederik Görg
Rb source
Differential pumping tube
K source
Ion pump
Titanium sublimationpump
MOTchamber
Glass cell20 cm
Mag
netic
tran
spor
t
Mag
neto
-opt
ical
trap
(MO
T)
Mic
rowa
ve e
vapo
ratio
nin
mag
netic
trap
(QU
IC)
Stat
e pr
epar
atio
n
Imag
ing
Read
out
Opt
ical
latti
ce e
xper
imen
t
Coo
ling
in d
ipol
e tra
pPr
epar
atio
n of
spi
n m
ixtu
re
Opt
ical
mol
asse
sO
ptic
al p
umpi
ng
time (s)
0 20 3010 40 50
Ion pump
MOT chamber Glass cell
x
z
y
Lattice team: Kilian Sandholzer, Joaquín Minguzzi, Anne-Sophie Walter, Konrad Viebahn, and Tilman EsslingerInstitute for Quantum Electronics, ETH Zurich
Strongly-correlated fermions in optical lattices - apparatus