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Aluminium Kinetic Inductance Detectors at 1.54 THz limited by photon noise and
generation-recombination noise
Pieter de Visser, Jochem Baselmans, Juan Bueno, Nuria Llombart, Teun Klapwijk
SRONTU Delft, Faculty of Applied SciencesTU Delft, Faculty of Electrical Engineering Mathematics and Computer Siences
Optical Noise Equivalent Power @ 1.54 THz
10-6
10-4
10-2
100
102
10-19
10-18
10-17
10-16
Optical Power (fW)
Op
tica
l NE
P (
W/H
z1/2 )
Measured Optical NEPPhoton Noise NEPPhoton Noise NEP+ Excess-qp GR-Noise
GR - NoisePhoton Noise
Operation principle
F0
f
S21
[dB
]
F [Ghz] Day et al, Nature 425, 817 (2003)
2Δ
Cooper Pairs
Quasiparticles
h
Photons break Cooper pairs => quasiparticlesHigher resistance and kinetic inductanceDip depth / amplitude: resistanceResonant frequency / phase: inductance
Anticipated fundamental limits
KID is a pair breaking detector: fluctuations in the quasiparticle number• Photon noise (= generation noise)• Recombination noise
• Generation-recombination noise
Prediction from dark experiments: NEP of 2 x 10-19 W/Hz1/2 limited by the presence of excess quasiparticles
DesignAll Aluminium KID• Central Line: 50 nm Al• Groundplane: 100 nm Al• Halfwave resonator with isolated central strip• X-slot Antenna, broad band around 1.54 THz• 2 mm silicon elliptical lenses
Design suitable for higher frequencies >1.54 THz
Controlled optical setup
8 optical filters! Box-in-box setupBaselmans et al. JLTP 167, 360 (2012)J. Bueno, Poster 106 (Thursday)
Fundamental limit: Photon Noise
101
102
103
104
105
-100
-95
-90
-85
-80
-75
Po
we
r sp
ect
ral d
en
sity
(d
Bc/
Hz)
Frequency (Hz)
3 zW459 zW26 aW3 fW34 fW142 fW724 fW
10-6
10-4
10-2
100
102
10-4
10-3
Qu
asip
artic
le li
fetim
e (s
)
Optical Power (fW)
105
106
Nu
mbe
r o
f qu
asip
artic
les
MeasurementsFit
Optical Power (fW)
Random arrival rate of the optical photons
+ recombination noise
𝑆𝐴=2 h𝑃 𝐹 ( 𝑑𝐴𝑑 𝑃 )2 11+(2𝜋 𝑓 τ )2
Recombination time scales with as expected
Generation-recombination noise
De Visser et al. PRL 106, 167004 (2011)Wilson & Prober, PRL, 87, 067004 (2001)
Quasiparticle fluctuations
101
102
103
104
105
-95
-90
-85
-80
Frequency (Hz)
Am
plit
ud
e P
SD
(d
Bc/
Hz)
90 mK150 mK180 mK210 mK240 mK255 mK
100 150 200 250
10-4
10-3
Qu
asi
pa
rtic
le li
fetim
e (
s)
Temperature (mK)
105
106
Nu
mb
er
of q
ua
sip
art
icle
s
MeasurementsTheory
2
2 2 2 2
4 4
1 1N
N NS
𝑁𝐸𝑃 h𝑝 𝑜𝑡𝑜𝑛=√2 h𝑃 𝐹η𝑜𝑝𝑡
101
102
103
104
105
10-19
10-18
10-17
10-16
Am
plitu
de N
EP
(W
/Hz
1/2
)
Frequency (Hz)
3 zW43 zW455 zW4 aW26 aW123 aW434 aW3 fW34 fW142 fW366 fW724 fW
Optical Noise Equivalent Power
10-6
10-4
10-2
100
102
10-19
10-18
10-17
10-16
Optical Power (fW)O
ptic
al N
EP
(W
/Hz1/
2 )
Measured Optical NEPPhoton Noise NEPPhoton Noise NEP+ Excess-qp GR-Noise
GR - Noise
Photon Noise
Photon noise limited NEP => Measure of optical efficiency: 48%
𝑁𝐸𝑃= √𝑆𝑝𝑒𝑐𝑡𝑟𝑢𝑚𝑅𝑒𝑠𝑝𝑜𝑛𝑠𝑖𝑣𝑖𝑡𝑦
(1+ (2𝜋 𝑓 τ )2)
Optical responsivity + lifetime: Microwave readout power dependent
-110 -105 -100 -95 -90
1014
1015
Microwave readout power (dBm)
Am
plitu
de R
espo
nsiv
ity (
W-1
)
Measurementsfit
-102 -98 -94 -90
1.5
2
2.5
3
3.5
4
Microwave readout Power (dBm)
Qu
asi
pa
rtic
le li
fetim
e (
ms)
De Visser et al. APL 100, 162601 (2012)Goldie, SuST, 26, 015004 (2013)
Microwave readout power: Excess quasipartilces AND nonlinear reponse due to
redistribution of quasiparticles
arXiv: 1306.4992
Poster 104 (Monday)
104
105
106
107
Inte
rnal Q
ualit
y F
acto
r
Model -100 dBm -80 dBm -72 dBm
0.1 0.15 0.2 0.25 0.3 0.355.288
5.2885
5.289
5.2895
Temperature (K)
Reso
nan
t F
reque
ncy
(G
Hz)
Measurement-100 dBm-90 dBm-80 dBm-72 dBm-68 dBm-64 dBm
(b)
0
0.05
0.1
0.15
0.2
E/
103
fE
120 mK
1 2 3 4 510
-3010
-2010
-10
E/
f E
1 1.2 1.4 1.6 1.8 20
0.5
1
1.5
E/10
3
fE
320 mK
1 2 3
10-8
10-6
10-4
E/
f E
-100 dBm-80 dBm-72 dBmThermal
Summary• Kinetic Inductance Detector at 1.54 THz
– Fundamental noise sources for pair breaking detectors revealed:
• Photon noise limited• Generation-recombination noise => excess quasiparticles
– NEP 3.8 x 10-19 W/Hz1/2, 48% optical efficiency • Well controlled optical setup, large power range
1.54 THz experiment - arXiv:1306.4238Microwave response - arXiv:1306.4992