Polariton transistor
Transcript of Polariton transistor
Polariton transistor: towards all-optical logics
Fluids of polaritons for optical logics: the polariton transistor
All-optical devices, a small overview
Daniele Sanvitto
D. Ballarini, M. De Giorgi, G. Gigli
Polariton, bistability and switches
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E. Cancellieri, E. Giacobino, A. Bramati
F. Marchetti, C. Tejedor
M. H. Szymanska
Work done in collaboration with
ESF Workshop - MIFP 2012 D. Sanvitto
The transistor…
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Address
Control
Output
Characteristics
Switching power
Area:
Low cost
50 x 50 nm
CMOS X 4 10-2 µm2
100 aJ
Operation speed
The transistor…
best performance 50 GHz
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Almeida et al Nature, 431 1081 (2004)
“All-optical control of light in a silicon chip”
Transmission can be changed in 500 ps with pulse energies of 25 pJ
Time limited by carrier decay
Optical devices…
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Belotti et al. Opt. Express 18, 1450 (2010)
“All-optical switching in SOI photonic wire nano-cavities”
Switching power of 0.1 pJ in an area of 5 µm2 ns speed modulation
Optimised V/Q2 for low power switching
Optical devices…
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Nozaki et al. Nat. Phot. 4, 477 (2010)
“Sub-femtojoule all-optical switching using a photonic-crystal nanocavity”
Switching power of 0.5 fJ with an operative area of many µm2 speed modulation in tenths of ps
Using of relatively small Q but very small V
Optical devices…
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Ferrera et al. Nat. Comm. 1, 29 (2010)
“On-chip CMOS-compativle all-optical integrator”
Very high Q 106 but fast switch time 8 ps
Ring cavity for integration operations
Optical devices…
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Switching energy of 0.3 fJ with a pulse of 1 ns
“Low-switching-energy and high-repetition-frequency all-optical flip-flop operations of a polarization bistable vertical-cavity surface-emitting laser”
Mori et al. App. Phys. Lett. 88, 101102 (2006)
Optical devices…
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What are the possibilities to use polariton fluids as switchers and amplifiers?
Polariton fluids for optical logics…
Inputs
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GaAs/AlGaAs based microcavity structure
Polaritons in semiconductor microcavities
h+
e-
+
Top DBR
Bottom DBR
Cavity
-3 -2 -1 0 1 2 3
1.526
1.528
1.530
1.532
En
erg
y (
eV
)
k (m-1)
Light
Matter Polaritons
Advantages
Short lifetimes and very fast propagation speeds
Strong non-linearities
Easy mode tuning
Possibility of operations with coherent particles
Integration with present semiconductor tecnology
bistability, OPO, TOPA, gain
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D. M. Whittaker, Phys. Rev. B 71, 115301 (2005) See also Gippius et al., Europhys. Lett. 67, 997 (2004)
Baas et al. Phys. Rev. A 69, 023809 (2004)
Towards a polariton logic
Bistability in polariton microcavities
ESF Workshop - MIFP 2012 D. Sanvitto
Liew, et al. Phys Rev. Lett. 101, 016402 (2008)
“Optical circuits based on polariton neurons…”
Towards a polariton logic
ESF Workshop - MIFP 2012 D. Sanvitto
Paraiso et al. Nat. Mat. 9, 655 (2010)
Independent bistable, or multistable behaviour for different polariton spin populations
Towards a polariton logic
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Amo et al. Nat. Phot. 4, 361 (2010)
Polariton switch using two degenerate beams: Switching energies in fJ range + propagation
Towards a polariton logic
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Degenerate two pumps experiment showing an AND gate behaviour
Leyder et al. Phys. Rev. Lett 99, 196402 (2007)
Towards a polariton logic
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- Complete logic functionality (NOR or NAND gate)
- Cascadability – the output of one stage must be in the correct form to drive the input of the
next stage (interchangeability of input and output)
- Fan Out – the output of one stage must be sufficient to drive the input of at least two
subsequent stages (fan out or signal gain of at least two)
- Logic-level restoration
- Input-output isolation
Criteria for practical optical logic:
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Low power On resonance High power
On/Off for a resonant pump
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Cancellieri et al. Phys. Rev. Lett. 108, 065301 (2012) See also Phys. Rev. B 83, 214507 (2011)
Interaction and behaviour of two non degenerate fluids in the microcavity
Influence of two fluids on each other superfluidity/supersonicity
ESF Workshop - MIFP 2012 D. Sanvitto
-5 -4 -3 -2 -1 0 1 2 3 4 5
1,479
1,480
1,481
1,482
1,483
1,484
1,485
1,486
Energ
y (e
V)
k// (m
-1)
0 20 40 60 80 100 120 140 160 180 200 220-0,1
0,0
0,1
0,2
0,3
0,4
0,5
0,6
0,7
0,8
0,9
1,0
1,1
S2
No
rmaliz
ed E
mis
sio
n In
tensity
(a.u
.)
Input Power
0 20 40 60 80 100 120 140 160 180 200 220-0,1
0,0
0,1
0,2
0,3
0,4
0,5
0,6
0,7
0,8
0,9
1,0
1,1
S1
Norm
aliz
ed E
mis
sio
n In
tensity
(a.u
.)
Input Power
Polariton bistability with two fluids
Bistability of two independent pump states
P2
P1
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Polariton transistor
ESF Workshop - MIFP 2012 D. Sanvitto
Polariton transistor
Address Control
Independent control and address states
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Polariton transistor
Effect of the control on the address switching
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Polariton transistor
The intrinsic power to switch polariton is a few atto Joule
Fixing the address power the control undergoes a strong gain
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Changes of the control gain with detuning of the address from the LPB
Polariton transistor
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Far field
A
B C
A B
B+C A
A
B C
Below threshold
Above threshold
Real space
Two addresses A and B, one control C
Two polariton transistors in a cascade experiment
30 µm
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0 10 20 30 40 50
Pump power (mW)
Sig
nal E
mis
sio
n
How fast is the transition on/off and off/on ?
-3 -2 -1 0 1 2 3 4
1,485
1,490
1,495
1,500
1,505
1,510
Energ
y (
eV
)
kx (m
-1)
On
Off
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-200 0 200 400 600 800 1000 1200 1400 1600
Time (ps)
Pcw
= 30 mW
Ppulsed
= 41 mW
Inte
nsi
ty E
mis
sion (
a.u.
)
-200 0 200 400 600 800 1000 1200 1400 1600
Inte
nsity
Em
issio
n (
a.u
.)
Time (ps)
Pcw
= 3.3 mW
Ppulsed
= 6 mW
(d)
(c)
Streak image Streak image
The state is off and the pulse arriving it pushes it to resonance
The state is on and the arrival of the pulse reduces the emission down
How fast is the transition on/off and off/on ?
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-200 0 200 400 600 800 1000 1200 1400 1600
0
100
200
300
400
500
600
700
K
1 S
ign
al E
mis
sio
n In
tesity (
a. u
.)
Time (ps)
P1mW
P2.5mW
P3.3mW
P4mW
Effect of pump power on the intensity of the on signal
ESF Workshop - MIFP 2012 D. Sanvitto
-200 0 200 400 600 800 1000120014001600
300
600
900
0 mW
6 mW
41 mW
54 mW
Sig
nal E
mis
sio
n Inte
nsity (
arb
. uni.)
Time (ps)
Effect of pump power on the intensity of the on signal
ESF Workshop - MIFP 2012 D. Sanvitto
-200 0 200 400 600 800 1000 1200 1400 1600 1800
10000
Inte
nsity
(a.u
.)
Time (ps)
Double switch using two probes at k1 and k2