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| | | 4th of October 2024 helg@hi.is www.liquid-light.fuw.edu.pl | | |
Dirac exciton–polariton condensates in photonic crystal gratings
Helgi Sigurðsson
HPM 2024
helg@hi.is www.liquid-light.fuw.edu.pl
UNIVERSITY OF WARSAW
Dirac exciton–polariton condensates in photonic crystal
gratings
Helgi Sigurðsson
HPM 2024
Vincenzo Ardizzone
Special thanks to
Hai Son Nguyen
Hai Chau Nguyen
Daniele Sanvitto
Dimitrios Trypogeorgos
Antonio Gianfrate
Ioannis Georgakilas
Experiment
Theory
Dario Ballarini
Fabrizio Riminucci, Maria Efthymiou-Tsironi, Kirk W. Baldwin,
Loren N. Pfeiffer, Milena De Giorgi
helg@hi.is www.liquid-light.fuw.edu.pl
UNIVERSITY OF WARSAW
Dirac exciton–polariton condensates in photonic crystal
gratings
Helgi Sigurðsson
HPM 2024
Outline of talk
Newer results
Polaritons in a saddle dispersion
Variable ballistic-evanescent coupling
Results
Negative mass optical trapping
Evanescently coupled polariton condensates and chains
Introduction
Subwavelength dielectric gratings
Polariton condensation in bound states in the continuum
Ardizzone et al., Nature 605, 447 (2022)
Gianfrate, HS, et al., Nat. Phys. 20, 61 (2024)
HS et al., Nanophotonics 13, 3503 (2024)
Georgakilas, Gianfrate, HS, Trypogeorgos
et al., Work in progress
helg@hi.is www.liquid-light.fuw.edu.pl
UNIVERSITY OF WARSAW
Dirac exciton–polariton condensates in photonic crystal
gratings
Helgi Sigurðsson
HPM 2024
A bound state in the continuum (BIC) is an exception to conventional leaky resonances. A BIC lies inside the continuum and coexists with extended waves, but it remains perfectly confined without any radiation.
Bound states in the continuum
General wave phenomenon
Studied in: Quantum mechanics – Acoustics – Photonics - Elastic waves in solids - etc
Lossy wave-mechanical system
Continuum
Hsu et al., Nat. Rev. Mat. 1, 16048 (2016) ; Zhong et al., Materials 16(22), 7112 (2023)
Nanophotonics
helg@hi.is www.liquid-light.fuw.edu.pl
UNIVERSITY OF WARSAW
Dirac exciton–polariton condensates in photonic crystal
gratings
Helgi Sigurðsson
HPM 2024
Polarization vortices associated with photonic BICs
Bo Zhen, Marin Soljačić et al, Phys. Rev. Lett. 113, 257401 (2014)
Photonic crystal slabs
helg@hi.is www.liquid-light.fuw.edu.pl
UNIVERSITY OF WARSAW
Dirac exciton–polariton condensates in photonic crystal
gratings
Helgi Sigurðsson
HPM 2024
Photonic slab waveguide
Totally intern reflected guided modes lie beneath the light cone
Photonic grating – Period a
1D modulation folds modes across the Brillouin zone and into the light cone
“How to shape photonic band on-demand and taming their losses at will”, Hai Son Nguyen (2024)
Simple mirror-symmetric photonic structures: gratings
Coupling to the continuum possible!
Energy cannot leak outside (TIR)
Bragg replica
Polarization
helg@hi.is www.liquid-light.fuw.edu.pl
UNIVERSITY OF WARSAW
Dirac exciton–polariton condensates in photonic crystal
gratings
Helgi Sigurðsson
HPM 2024
H. Sigurðsson, H. C. Nguyen, H. S. Nguyen, "Dirac exciton–polariton condensates in photonic crystal gratings" Nanophotonics, (2024)
Lu et al., Phot. Res. 8, A91 (2020) ; Suh et al., IEEE Journ. of Quant. Elec. 40, 1511 (2004) ; Friedrich and Wintgen Phys. Rev. A 32, 3231 (1985)
Symmetric and antisymmetric eigenstates with complex frequencies
Hai Son Nguyen
BIC
Radiative channel
Can be tuned!
helg@hi.is www.liquid-light.fuw.edu.pl
UNIVERSITY OF WARSAW
Dirac exciton–polariton condensates in photonic crystal
gratings
Helgi Sigurðsson
HPM 2024
H. Sigurðsson, H. C. Nguyen, H. S. Nguyen, "Dirac exciton–polariton condensates in photonic crystal gratings" Nanophotonics, (2024)
BIC!
helg@hi.is www.liquid-light.fuw.edu.pl
UNIVERSITY OF WARSAW
Dirac exciton–polariton condensates in photonic crystal
gratings
Helgi Sigurðsson
HPM 2024
A simple coupled-oscillator model describes how symmetric and antisymmetric guided modes mix with excitons, forming polaritons
Model of exciton-polaritons in the grating
Photons
Excitons
Lower “Dirac” polaritons
H. Sigurðsson, H. C. Nguyen, H. S. Nguyen, "Dirac exciton–polariton condensates in photonic crystal gratings" Nanophotonics, (2024)
helg@hi.is www.liquid-light.fuw.edu.pl
UNIVERSITY OF WARSAW
Dirac exciton–polariton condensates in photonic crystal
gratings
Helgi Sigurðsson
HPM 2024
Mean field modeling
Generalized Gross-Pitaevskii equation for forward and backward propagating polaritons
Sigurðsson et al., "Dirac exciton–polariton condensates in photonic crystal gratings" Nanophotonics, 2024
Nigro & Gerace, Phys. Rev. B 108, 085305 (2023)
Riminucci et al., Phys. Rev. Lett 131, 246901 (2023)
Simulations – increasing power
Bichromatic condensate solutions
helg@hi.is www.liquid-light.fuw.edu.pl
UNIVERSITY OF WARSAW
Dirac exciton–polariton condensates in photonic crystal
gratings
Helgi Sigurðsson
HPM 2024
H. Sigurðsson, H. C. Nguyen, H. S. Nguyen, "Dirac exciton–polariton condensates in photonic crystal gratings" Nanophotonics, (2024)
H. S. Nguyen, et al., Phys. Rev. Lett. 120, 066102 (2018)
helg@hi.is www.liquid-light.fuw.edu.pl
UNIVERSITY OF WARSAW
Dirac exciton–polariton condensates in photonic crystal
gratings
Helgi Sigurðsson
HPM 2024
Losses vs localization: Recall the general radiation interference condition (losses)
Critical point
Critical point – Mixed ballistic-trapped condensates
Driven zitterbewegung oscillations
Sigurðsson et al., "Dirac exciton–polariton condensates in photonic crystal gratings" Nanophotonics, 2024
Small
pump
Wide
pump
+
-
+
-
helg@hi.is www.liquid-light.fuw.edu.pl
UNIVERSITY OF WARSAW
Dirac exciton–polariton condensates in photonic crystal
gratings
Helgi Sigurðsson
HPM 2024
Resonant mode: Ballistic BEC
Localized nonresonant optical pumping
Pump blueshift
Ohadi et al., PRX 6, 031032 (2016)
Töpfer, Sigurðsson, et al., Commun. Phys. 3, 2 (2020)
Pump
Upper polaritons
Lower polaritons
Conventional planar Fabry-Pérot cavities
Convex lower dispersion: Positive effective mass
Optical trapping
Gap-confined BIC+BEC
Pump blueshift
Gianfrate, Sigurðsson, et al., Nat. Phys. 20, 61 (2024)
Pump
NEW: Polariton subwavelength gratings
Concave lower dispersion: Negative effective mass
Credit: Mateusz Król, FUW
helg@hi.is www.liquid-light.fuw.edu.pl
UNIVERSITY OF WARSAW
Dirac exciton–polariton condensates in photonic crystal
gratings
Helgi Sigurðsson
HPM 2024
BICs in light-matter systems:
Exciton-polariton condensates
Ardizzone et al., “Polariton Bose–Einstein condensate from a bound state in the continuum” Nature 605, 447 (2022)
Kravtsov et al., „Nonlinear polaritons in a monolayer semiconductor coupled to optical bound states in the continuum” Light: Sci. & Appl. 9, 56 (2020)
Tohru Fujita, et al., „Tunable polariton absorption of distributed feedback microcavities at room temperature„ Phys. Rev. B 57, 12428 (1998)
Sample
[1] Ardizzone et al., “Polariton Bose–Einstein condensate from a bound state in the continuum” Nature 605, 447 (2022)
[2] Kravtsov et al., Light: Sci. & Appl. 9, 56 (2020)
[3] Tohru Fujita, et al., Phys. Rev. B 57, 12428 (1998)
Photoluminescence
Effective non-Hermitian Dirac polariton model
Experiment
Polariton lifetime
Quasi
BIC
BIC
BIC condensate
helg@hi.is www.liquid-light.fuw.edu.pl
UNIVERSITY OF WARSAW
Dirac exciton–polariton condensates in photonic crystal
gratings
Helgi Sigurðsson
HPM 2024
Gianfrate, Sigurðsson, et al., Nat. Phys. 20, 61 (2024)
Effective non-Hermitiab polariton Dirac Hamiltonian with a potential term
Below threshold
Above threshold
BIC BEC
Simulation
Real space
Fourier
space
Pump blueshift
(gap-confined)
helg@hi.is www.liquid-light.fuw.edu.pl
UNIVERSITY OF WARSAW
Dirac exciton–polariton condensates in photonic crystal
gratings
Helgi Sigurðsson
HPM 2024
Reconfigurable optical tight-binding systems with condensate-BICs
Evanescent coupling leads to formation of
Complexes of condensates (2024)
Gianfrate, Sigurðsson, et al., Nat. Phys. 20, 61 (2024)
Two pumps (close)
Two pumps (far apart)
helg@hi.is www.liquid-light.fuw.edu.pl
UNIVERSITY OF WARSAW
Dirac exciton–polariton condensates in photonic crystal
gratings
Helgi Sigurðsson
HPM 2024
Gianfrate, Sigurðsson, et al., Nat. Phys. 20, 61 (2024)
Optically simulated bonding of condensates
Two pumps (close)
Two pumps (far apart)
helg@hi.is www.liquid-light.fuw.edu.pl
UNIVERSITY OF WARSAW
Dirac exciton–polariton condensates in photonic crystal
gratings
Helgi Sigurðsson
HPM 2024
Singular optics
Optical control over the BIC topological charge distribution
Symmetry protected BIC nature: Polarization vortices in the far field
Gianfrate, Sigurðsson, et al., Nat. Phys. 20, 61 (2024)
Zhen et al, Phys. Rev. Lett. 113, 257401 (2014)
Charges increase!
helg@hi.is www.liquid-light.fuw.edu.pl
UNIVERSITY OF WARSAW
Dirac exciton–polariton condensates in photonic crystal
gratings
Helgi Sigurðsson
HPM 2024
Chain of 10 pump spots: Optically induced polariton Bloch bands – dispersion engineering
„mono-atomic”
„di-atomic (SSH)”
Experiment PL
Theory
Gianfrate, Sigurðsson, et al., Nat. Phys. 20, 61 (2024)
helg@hi.is www.liquid-light.fuw.edu.pl
UNIVERSITY OF WARSAW
Dirac exciton–polariton condensates in photonic crystal
gratings
Helgi Sigurðsson
HPM 2024
Georgakilas, Gianfrate, HS, Trypogeorgos et al., Work in progress
Grudinina, Voronova, et al., Nat. Comm. 14 3464 (2023)
K-space
R-space
helg@hi.is www.liquid-light.fuw.edu.pl
UNIVERSITY OF WARSAW
Dirac exciton–polariton condensates in photonic crystal
gratings
Helgi Sigurðsson
HPM 2024
Two-pump spots
Blue arrows show mass flow towards pump spots (negative mass)
Red arrows show mass flow away from pump spots (positive mass)
Ballistic coupling
Evanscent coupling
Theory
Experiment
helg@hi.is www.liquid-light.fuw.edu.pl
UNIVERSITY OF WARSAW
Dirac exciton–polariton condensates in photonic crystal
gratings
Helgi Sigurðsson
HPM 2024
Theory
Experiment (photoluminescence)
Evanescent regime
Ballistic regime
helg@hi.is www.liquid-light.fuw.edu.pl
UNIVERSITY OF WARSAW
Dirac exciton–polariton condensates in photonic crystal
gratings
Helgi Sigurðsson
HPM 2024
Competitition between evanescent and ballistic interactions on a larger scale
helg@hi.is www.liquid-light.fuw.edu.pl
UNIVERSITY OF WARSAW
Dirac exciton–polariton condensates in photonic crystal
gratings
Helgi Sigurðsson
HPM 2024
Summary and perspectives
helg@hi.is www.liquid-light.fuw.edu.pl
UNIVERSITY OF WARSAW
Dirac exciton–polariton condensates in photonic crystal
gratings
Helgi Sigurðsson
HPM 2024
THE EXCITON-POLARITON GROUP�
http://polariton.fuw.edu.pl/
EIC Pathfinder Open – 2023 „QUONDENSATE”
EIC Pathfinder Open – 2023 „PolArt”
EIC Pathfinder Challenges – 2022 „Q-One”
Prof. Michał Matuszewski
Dr. Andrzej Opala
LIQUID LIGHT RESEARCH GROUP
www.liquid-light.fuw.edu.pl
helg@hi.is www.liquid-light.fuw.edu.pl
UNIVERSITY OF WARSAW
Dirac exciton–polariton condensates in photonic crystal
gratings
Helgi Sigurðsson
HPM 2024
www.oecs19.pl
Chairs:
Prof. Barbara Piętka
Prof. Michał Matuszewski
helg@hi.is www.liquid-light.fuw.edu.pl
UNIVERSITY OF WARSAW
Dirac exciton–polariton condensates in photonic crystal
gratings
Helgi Sigurðsson
HPM 2024
BONUS SLIDES
helg@hi.is www.liquid-light.fuw.edu.pl
UNIVERSITY OF WARSAW
Dirac exciton–polariton condensates in photonic crystal
gratings
Helgi Sigurðsson
HPM 2024
Tohru Fujita, et al., „Tunable polariton absorption of distributed feedback microcavities at room temperature„ Phys. Rev. B 57, 12428 (1998)
Alexander L. Yablonskii et al., „Polariton Effect in Distributed Feedback Microcavities” J. Phys. Soc. Jpn. 70, 1137(2001)
Experiments in light-matter systems: distributed feedback microcavity polaritons with perovskites at room temperature
Earliest polariton BIC observation but not called a „BIC”
helg@hi.is www.liquid-light.fuw.edu.pl
UNIVERSITY OF WARSAW
Dirac exciton–polariton condensates in photonic crystal
gratings
Helgi Sigurðsson
HPM 2024
Bound states in the continuum: Interference of radiation
Temporal coupled mode theory: Two coupled resonances also couple via a mutual loss channel (continuum)
When the following condition is met, one eigenvalue takes all the losses and the other becomes lossless
Radiative channel
helg@hi.is www.liquid-light.fuw.edu.pl
UNIVERSITY OF WARSAW
Dirac exciton–polariton condensates in photonic crystal
gratings
Helgi Sigurðsson
HPM 2024
A simple coupled-oscillator model describes how symmetric and antisymmetric guided modes mix with excitons, forming polaritons
Sigurðsson et al., "Dirac exciton–polariton condensates in photonic crystal gratings" Nanophotonics, 2024
In particular, the lower polariton branches can be approximated as…
Model of Dirac BIC exciton-polaritons
Photons
Excitons
helg@hi.is www.liquid-light.fuw.edu.pl
UNIVERSITY OF WARSAW
Dirac exciton–polariton condensates in photonic crystal
gratings
Helgi Sigurðsson
HPM 2024
Two complementing forces towards polariton condensation in 1D gratings
Low losses of BIC help polaritons undergo stimulation and condense
Localized pumping lifts the condensate into the gap – confinement
helg@hi.is www.liquid-light.fuw.edu.pl
UNIVERSITY OF WARSAW
Dirac exciton–polariton condensates in photonic crystal
gratings
Helgi Sigurðsson
HPM 2024
Previous polariton trapping techniques: annular pumps, micropillars, mesas, etc
Annular nonresonant laser profile focused on the cavity plane
Askitopoulos et al., Phys. Rev. B 88, 041308(R) (2013);
Cristofolini et al., Phys. Rev. Lett. 110, 186403 (2013)
(NEW) Negative mass optical trapping (+BIC)!
2024
Not very efficient:
Polariton gain is around the condensate – small overlap
Conventional polariton optical trapping
helg@hi.is www.liquid-light.fuw.edu.pl
UNIVERSITY OF WARSAW
Dirac exciton–polariton condensates in photonic crystal
gratings
Helgi Sigurðsson
HPM 2024
Last bit: Very recent results
Georgakilas, Gianfrate, Trypogeorgos, Sigurðsson – In preparation
Grating direction
Single pumped condensate
Hyperbolic isofrequency contours
Fast vs slow phase fronts
Ballistic coupling
Evanscent coupling
Two pumped condensate: Crossover from evanescent to ballistic coupling
helg@hi.is www.liquid-light.fuw.edu.pl
UNIVERSITY OF WARSAW
Dirac exciton–polariton condensates in photonic crystal
gratings
Helgi Sigurðsson
HPM 2024
H. Sigurðsson, H. C. Nguyen, H. S. Nguyen, "Dirac exciton–polariton condensates in photonic crystal gratings" Nanophotonics, (2024)
helg@hi.is www.liquid-light.fuw.edu.pl
UNIVERSITY OF WARSAW
Dirac exciton–polariton condensates in photonic crystal
gratings
Helgi Sigurðsson
HPM 2024
Slab waveguide
Grated waveguide
Grated waveguide with QWs
Ardizzone et al., Nature 605, 447 (2022)
helg@hi.is www.liquid-light.fuw.edu.pl
UNIVERSITY OF WARSAW
Dirac exciton–polariton condensates in photonic crystal
gratings
Helgi Sigurðsson
HPM 2024
helg@hi.is www.liquid-light.fuw.edu.pl
UNIVERSITY OF WARSAW
Dirac exciton–polariton condensates in photonic crystal
gratings
Helgi Sigurðsson
HPM 2024
helg@hi.is www.liquid-light.fuw.edu.pl
UNIVERSITY OF WARSAW
Dirac exciton–polariton condensates in photonic crystal
gratings
Helgi Sigurðsson
HPM 2024
Grating makes a difference between the nearfield and the farfield densitites
helg@hi.is www.liquid-light.fuw.edu.pl
UNIVERSITY OF WARSAW
Dirac exciton–polariton condensates in photonic crystal
gratings
Helgi Sigurðsson
HPM 2024
helg@hi.is www.liquid-light.fuw.edu.pl
UNIVERSITY OF WARSAW
Dirac exciton–polariton condensates in photonic crystal
gratings
Helgi Sigurðsson
HPM 2024
helg@hi.is www.liquid-light.fuw.edu.pl
UNIVERSITY OF WARSAW
Dirac exciton–polariton condensates in photonic crystal
gratings
Helgi Sigurðsson
HPM 2024
helg@hi.is www.liquid-light.fuw.edu.pl
UNIVERSITY OF WARSAW
Dirac exciton–polariton condensates in photonic crystal
gratings
Helgi Sigurðsson
HPM 2024
[Cilibrizzi et al., APL 105, 191118 (2014)]
Photon
Photoexcitation of excitons
Strong light-matter coupling achieved in high-Q cavities
Strong light-matter coupling leads to new eigenmodes: exciton-polaritons
helg@hi.is www.liquid-light.fuw.edu.pl
UNIVERSITY OF WARSAW
Dirac exciton–polariton condensates in photonic crystal
gratings
Helgi Sigurðsson
HPM 2024
Incoherent excitation: Power-driven polariton phase transition into a condensate
Light from polariton condensates
Balili et al., Science 316, 1007 (2007)
Photonic losses out of cavity: Coherent light source
Phonon-exciton relaxation
Bosonic final-state stimulated scattering
Excited charge carriers
The nonresonant excitation feeds the condensate with particles and also creates a reservoir of uncondensed particles (mostly excitonic) at higher momenta.
“Hot” exciton reservoir
Condensate
Credit: Mateusz Król
helg@hi.is www.liquid-light.fuw.edu.pl
UNIVERSITY OF WARSAW
Dirac exciton–polariton condensates in photonic crystal
gratings
Helgi Sigurðsson
HPM 2024