Ultrafast room-temperature single photon emission from quantum dots ...
Supporting Information:
Ultrafast room-temperature single photon emission from quantum dots coupled to plasmonic nanocavities Thang B. Hoang1,2,†, Gleb M. Akselrod2,3,†, Maiken H. Mikkelsen1,2,3,* 1
Department of Physics, Duke University, Durham, NC 27708, USA,
2
Center for Metamaterials and Integrated Plasmonics, Duke University, Durham, NC 27708, USA
3
Department of Electrical and Computer Engineering, Duke University, Durham, NC 27708, USA †
These authors contributed equally to this work. *e-mail: [email protected]
1
Field enhancement in the nanocavity Full-wave simulations of the nanocavities were performed using the finite-element software COMSOL Multiphysics. The field enhancement in the nanocavity was computed based on the scattered-field formulation, where the scattered fields are obtained by subtracting them from the analytical solution of an incident plane wave in the absence of the nanocavity. The dominant field in the nanocavity is in the z-direction, the direction between the metal film and the nanocube. At the excitation wavelength λ = 488 nm, the maximum field enhancement in the zdirection is a factor ~15 relative to free space, and occurs near the corners of the nanocavity (Figure S1). To compute the spontaneous emission enhancement shown in Figure 1d in the main text, we used the Green’s function formalism. The QD was modelled as a monochromatic point-dipole emitting at the resonance of the fundamental nanocavity resonance.1 The Green's function was calculated at each position in the nanocavity by varying the position of the dipole emitter on a discrete 15×15 grid placed beneath the nanocube.
Figure S1. Enhancement in the electric field in the z-direction at λ = 488 nm as a function of position under the nanocube. For an optimally coupled QD near the corner of the nanocavity (indicated by the red dot), the enhancement in the field intensity is a factor of ~15.
2
Measurements of additional nanocavity coupled QDs Photon correlation and time-resolved emission measurements were performed on 12 nanocavities in addition to the data presented in Figures 2-4 in the main text. Figure S2 shows the photon correlation curves from two additional nanocavities, showing that a single QD is coupled to these cavities. The fast component of the photoluminescence lifetime is in the range of 10-20 ps, as was the case for all the other nanocavities observed containing optimally coupled QDs.
Figure S2. Measured photon correlation function and time-resolved photoluminescence (PL) for two representative nanocavities coupled to a single QD, in addition to the results presented in the main text. The instrument response function (IRF) is also shown (light gray). Similar data were obtained for ~10 additional nanocavities. References (1)
Ciraci, C.; Rose, A.; Argyropoulos, C.; Smith, D. J. Opt. Soc. Am. B 2014, 31, 2601–2607.
3
Ultrafast room-temperature single photon emission from quantum dots coupled to plasmonic nanocavities Thang B. Hoang1,2,†, Gleb M. Akselrod2,3,†, Maiken H. Mikkelsen1,2,3,* 1
Department of Physics, Duke University, Durham, NC 27708, USA,
2
Center for Metamaterials and Integrated Plasmonics, Duke University, Durham, NC 27708, USA
3
Department of Electrical and Computer Engineering, Duke University, Durham, NC 27708, USA †
These authors contributed equally to this work. *e-mail: [email protected]
1
Field enhancement in the nanocavity Full-wave simulations of the nanocavities were performed using the finite-element software COMSOL Multiphysics. The field enhancement in the nanocavity was computed based on the scattered-field formulation, where the scattered fields are obtained by subtracting them from the analytical solution of an incident plane wave in the absence of the nanocavity. The dominant field in the nanocavity is in the z-direction, the direction between the metal film and the nanocube. At the excitation wavelength λ = 488 nm, the maximum field enhancement in the zdirection is a factor ~15 relative to free space, and occurs near the corners of the nanocavity (Figure S1). To compute the spontaneous emission enhancement shown in Figure 1d in the main text, we used the Green’s function formalism. The QD was modelled as a monochromatic point-dipole emitting at the resonance of the fundamental nanocavity resonance.1 The Green's function was calculated at each position in the nanocavity by varying the position of the dipole emitter on a discrete 15×15 grid placed beneath the nanocube.
Figure S1. Enhancement in the electric field in the z-direction at λ = 488 nm as a function of position under the nanocube. For an optimally coupled QD near the corner of the nanocavity (indicated by the red dot), the enhancement in the field intensity is a factor of ~15.
2
Measurements of additional nanocavity coupled QDs Photon correlation and time-resolved emission measurements were performed on 12 nanocavities in addition to the data presented in Figures 2-4 in the main text. Figure S2 shows the photon correlation curves from two additional nanocavities, showing that a single QD is coupled to these cavities. The fast component of the photoluminescence lifetime is in the range of 10-20 ps, as was the case for all the other nanocavities observed containing optimally coupled QDs.
Figure S2. Measured photon correlation function and time-resolved photoluminescence (PL) for two representative nanocavities coupled to a single QD, in addition to the results presented in the main text. The instrument response function (IRF) is also shown (light gray). Similar data were obtained for ~10 additional nanocavities. References (1)
Ciraci, C.; Rose, A.; Argyropoulos, C.; Smith, D. J. Opt. Soc. Am. B 2014, 31, 2601–2607.
3
