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