Strong coupling between Tamm Plasmon and QW exciton
description
Transcript of Strong coupling between Tamm Plasmon and QW exciton
Strong coupling between Tamm Plasmon and
QW exciton
E. Homeyer, C. Symonds, A. Lemaitre* , J.C. Plenet, J. Bellessa
LPMCN (Laboratory of Physics of Condensed Mater and Nanostructures)University Claude Bernard Lyon 1, Lyon, France
* LPN (Laboratory For Photonics and Nanostructures), Marcoussis, France
PLMCN 2010, Cuernavaca, Mexico - April 15th 2010
• Introduction
Outline
• Plasmon in GaAs/GaAlAs heterostructures• Samples• Plasmon / heavy- and light-hole exciton mixing• Room temperature experiments
• Tamm plasmon states• Description of Tamm plasmons• Emission of Tamm/exciton polaritons
• ConclusionPLMCN 2010, Cuernavaca, Mexico - April 15th 2010
• Introduction
Outline
• Plasmon in GaAs/GaAlAs heterostructures• Samples• Plasmon / heavy- and light-hole exciton mixing• Room temperature experiments
• Tamm plasmon states• Description of Tamm plasmons• Emission of Tamm/exciton polaritons
• ConclusionPLMCN 2010, Cuernavaca, Mexico - April 15th 2010
Surface plasmons
• Surface plasmon : Interface metal / dielectric material
Introduction
• Near a luminescent source (Dye or QW)– Weak coupling regime– Strong coupling regime
Metal
Dielectric
– Damping ∟& // propagation– TM Mode only
PLMCN 2010, Cuernavaca, Mexico - April 15th 2010
Plasmon in weak coupling regime
Objective : enhancement of the spontaneous emission rate
PLMCN 2010, Cuernavaca, Mexico - April 15th 2010
Introduction
A Akimov et al., Nature. 450, 402 (2007)
Enhancement PL : 2.5 x
Coupling efficiency 60%
• For nanoparticles
Okamoto K et al. Nature Mat. 3 (9) 601 (2004)
A.Neogi, et al., Phys. Rev. B, 66,153305(2002)
• For active layers such as GaN/InGaN QW
– Enhancement SER 92 x
– Enhancement PL 17 x
• Semiconductor nanocrystals arrays : CdSe dots under a thin silver film
Rabi splitting of 112 meV
D.E. Gomez et al. Nano Lett. 10 274 (2010)
Plasmon in strong coupling
PLMCN 2010, Cuernavaca, Mexico - April 15th 2010
Introduction
Strong interaction between plasmons and :
• Aggregated dyes.
J. Bellessa, C. Bonnand, J.C. Plenet, J. Mugnier., PRL 93, 36404 (2004). T.K. Hakala et al. PRL 103 053602 (2009)
• Laser dyes such as Rhodamine 6G
Rabi splitting energies up to 230 meV.
• Introduction
Outline
• Plasmon in GaAs/GaAlAs heterostructures• Samples• Plasmon / heavy- and light-hole exciton mixing• Room temperature experiments
• Tamm plasmon states• Description of Tamm plasmons• Emission of Tamm/exciton polaritons
• ConclusionPLMCN 2010, Cuernavaca, Mexico - April 15th 2010
SamplesPlasmon in GaAs/GaAlAs heterostructures
GaAs
QW (x5)
1540 1550 1560 1570 1580
Xlh
Xhh
Lu
min
es
ce
nc
e (
arb
. u.)
Energy (meV)
• Samples elaborated in collaboration with A. Lemaître (LPN)
PLMCN 2010, Cuernavaca, Mexico - April 15th 2010
Silver
• Decoupling with a silver grating :
Silver
periodicity Λ = 250nm
Metal
Dielectric
1500 1550 1600
Xhh
60°
55°
50°
45°
40°
35°
30°
Ref
lect
ivity
Energy (meV)
25°
Xlh
Plasmon/heavy/light-exciton mixing
θ
• Reflectometry at 77K
Anticrossing plasmon/Xlh Strong coupling between SP and excitons
PLMCN 2010, Cuernavaca, Mexico - April 15th 2010
Plasmon in GaAs/GaAlAs heterostructures
Polaritons : -plasmon/-heavy hole exciton/-Light hole exciton
VXhh=22meV
VXlh=21meV
Xhhhhexc
Xlhlhexc
plasmonpl
iE
iE
ikE
H
02/
02/
2/2/)(
2
1
21
J. Bellessa, C. Symonds, C. Meynaud, J.C. Plenet, E. Cambril, A. Miard, L. Ferlazzo, and A. Lemaitre. Phys. Rev. B 78, 205326 (2008).PLMCN 2010, Cuernavaca, Mexico - April 15th 2010
Plasmon in GaAs/GaAlAs heterostructures
• Dispersion relation
Plasmon/heavy/light-exciton mixing
4,0 4,5 5,0 5,5 6,0 6,5 7,0 7,5 8,00,0
0,2
0,4
0,6
0,8
1,0
Plasmon Xhh Xlh
||2
Wavevector (µm-1)
• Mixing of Xhh & Xlh
XhhPlasmonXlh
• Still strong coupling @ RT
Rabi energy at resonance 20 meV
Room temperature experiments
PLMCN 2010, Cuernavaca, Mexico - April 15th 2010
Plasmon in GaAs/GaAlAs heterostructures
No polaritonic luminescence is present
• Introduction
Outline
• Plasmon in GaAs/GaAlAs heterostructures• Samples• Plasmon / heavy- and light-hole exciton mixing• Room temperature experiments
• Tamm plasmon states• Description of Tamm plasmons• Emission of Tamm/exciton polaritons
• ConclusionPLMCN 2010, Cuernavaca, Mexico - April 15th 2010
• Surface mode • Bragg mirror / metal layer• Very narrow linewidth • Direct coupling to
radiative light• TE and TM modes• Deep penetration length
A. V. Kavokin, I. A. Shelykh, and G. Malpuech, Phys. Rev. B 72, 233102 2005.M. E. Sasin, et al., Appl. Phys. Lett. 92, 251112 2008.
Description of Tamm plasmonsTamm plasmon states
PLMCN 2010, Cuernavaca, Mexico - April 15th 2010
Quantum wells in a Tamm structureTamm plasmon states
PLMCN 2010, Cuernavaca, Mexico - April 15th 2010
• Thick Bragg mirror to reduce the linewidth
GaAs substrate
AlAs
Al0.05Ga0.95As
25
• Silver film on top of the structure Tamm plasmon mode
• Inclusion of 2 InGaAs/AlGaAs QWs in the 15 last high refractive index layers
15
Silver film
Reflectometry experimentsTamm plasmon states
PLMCN 2010, Cuernavaca, Mexico - April 15th 201020 22 24 26 28 30 32
1430
1440
1450
1460
1470
(c)
Ene
rgy
(meV
)
Angle (°)
Ene
rgy
(meV
)
1430
1440
1450
1460
1470
1430 1440 1450 1460 1470 1480
(b)(b)
(b)
Energy (meV)
Ref
lect
iviy
(A
rb. u
nits
)
• Anticrossing between the exciton and the Tamm plasmon
• Rabi splitting : 12 meV
• Thin polariton lines compared to the splitting
• Simulations with a transfer matrix method
Luminescence of hybrid statesTamm plasmon states
PLMCN 2010, Cuernavaca, Mexico - April 15th 2010
• Strong emission at the low polariton energy
• Incoherent luminescence
• Emission in TE and TM polarisations
Conclusion
• Hybrid states plasmon/exciton in inorganic semiconductors
• Plasmon/Xlh/Xhh interaction energies of 21 and 22 meV
• Emission of Tamm plasmon/exciton polaritons
PLMCN 2010, Cuernavaca, Mexico - April 15th 2010