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Natalia G Berloff - One of the best experts on this subject based on the ideXlab platform.
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optical bistability under nonresonant excitation in spinor polariton Condensates
Physical Review Letters, 2018Co-Authors: Lucy Pickup, Alexis Askitopoulos, Kirill P Kalinin, Zacharias Hatzopoulos, Pavlos G. Savvidis, Natalia G Berloff, P G LagoudakisAbstract:: We realize bistability in the spinor of polariton Condensates under nonresonant optical excitation and in the absence of biasing external fields. Numerical modeling of the system using the Ginzburg-Landau equation with an internal Josephson coupling between the two spin components of the condensate qualitatively describes the experimental observations. We demonstrate that polariton spin bistability strongly depends on the condensate's overlap with the exciton reservoir by tuning the excitation geometry and sample temperature. We obtain noncollapsing bistability hysteresis loops for a record range of sweep times, [10 μs, 1 s], offering a promising route to spin switches and spin memory elements.
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nonresonant optical control of a spinor polariton condensate
Physical Review B, 2016Co-Authors: Alexis Askitopoulos, Kirill P Kalinin, Timothy Chi Hin Liew, Pasquale Cilibrizzi, Zacharias Hatzopoulos, Pavlos G. Savvidis, Natalia G BerloffAbstract:We investigate the spin dynamics of polariton Condensates spatially separated from and effectively confined by the pumping exciton reservoir. We obtain a strong correlation between the ellipticity of the non-resonant optical pump and the degree of circular polarisation (DCP) of the condensate at the onset of condensation. With increasing excitation density we observe a reversal of the DCP. The spin dynamics of the trapped condensate are described within the framework of the spinor complex Ginzburg-Landau equations in the Josephson regime, where the dynamics of the system are reduced to a current-driven Josephson junction. We show that the observed spin reversal is due to the interplay between an internal Josephson coupling effect and the detuning of the two projections of the spinor condensate via transition from a synchronised to a desynchronised regime. These results suggest that spinor polariton Condensates can be controlled by tuning the non-resonant excitation density offering applications in electrically pumped polariton spin switches.
Zacharias Hatzopoulos - One of the best experts on this subject based on the ideXlab platform.
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optical bistability under nonresonant excitation in spinor polariton Condensates
Physical Review Letters, 2018Co-Authors: Lucy Pickup, Alexis Askitopoulos, Kirill P Kalinin, Zacharias Hatzopoulos, Pavlos G. Savvidis, Natalia G Berloff, P G LagoudakisAbstract:: We realize bistability in the spinor of polariton Condensates under nonresonant optical excitation and in the absence of biasing external fields. Numerical modeling of the system using the Ginzburg-Landau equation with an internal Josephson coupling between the two spin components of the condensate qualitatively describes the experimental observations. We demonstrate that polariton spin bistability strongly depends on the condensate's overlap with the exciton reservoir by tuning the excitation geometry and sample temperature. We obtain noncollapsing bistability hysteresis loops for a record range of sweep times, [10 μs, 1 s], offering a promising route to spin switches and spin memory elements.
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nonresonant optical control of a spinor polariton condensate
Physical Review B, 2016Co-Authors: Alexis Askitopoulos, Kirill P Kalinin, Timothy Chi Hin Liew, Pasquale Cilibrizzi, Zacharias Hatzopoulos, Pavlos G. Savvidis, Natalia G BerloffAbstract:We investigate the spin dynamics of polariton Condensates spatially separated from and effectively confined by the pumping exciton reservoir. We obtain a strong correlation between the ellipticity of the non-resonant optical pump and the degree of circular polarisation (DCP) of the condensate at the onset of condensation. With increasing excitation density we observe a reversal of the DCP. The spin dynamics of the trapped condensate are described within the framework of the spinor complex Ginzburg-Landau equations in the Josephson regime, where the dynamics of the system are reduced to a current-driven Josephson junction. We show that the observed spin reversal is due to the interplay between an internal Josephson coupling effect and the detuning of the two projections of the spinor condensate via transition from a synchronised to a desynchronised regime. These results suggest that spinor polariton Condensates can be controlled by tuning the non-resonant excitation density offering applications in electrically pumped polariton spin switches.
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nonlinear optical spin hall effect and long range spin transport in polariton lasers
Physical Review Letters, 2012Co-Authors: Elena Kammann, Timothy Chi Hin Liew, Pasquale Cilibrizzi, Zacharias Hatzopoulos, Pavlos G. Savvidis, A. V. Kavokin, Hamid Ohadi, Panayiotis Tsotsis, P G LagoudakisAbstract:We report on the experimental observation of the nonlinear analogue of the optical spin Hall effect under highly nonresonant circularly polarized excitation of an exciton-polariton condensate in a GaAs/AlGaAs microcavity. The circularly polarized polariton Condensates propagate over macroscopic distances, while the collective condensate spins coherently precess around an effective magnetic field in the sample plane performing up to four complete revolutions.
Pavlos G. Savvidis - One of the best experts on this subject based on the ideXlab platform.
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optical bistability under nonresonant excitation in spinor polariton Condensates
Physical Review Letters, 2018Co-Authors: Lucy Pickup, Alexis Askitopoulos, Kirill P Kalinin, Zacharias Hatzopoulos, Pavlos G. Savvidis, Natalia G Berloff, P G LagoudakisAbstract:: We realize bistability in the spinor of polariton Condensates under nonresonant optical excitation and in the absence of biasing external fields. Numerical modeling of the system using the Ginzburg-Landau equation with an internal Josephson coupling between the two spin components of the condensate qualitatively describes the experimental observations. We demonstrate that polariton spin bistability strongly depends on the condensate's overlap with the exciton reservoir by tuning the excitation geometry and sample temperature. We obtain noncollapsing bistability hysteresis loops for a record range of sweep times, [10 μs, 1 s], offering a promising route to spin switches and spin memory elements.
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nonresonant optical control of a spinor polariton condensate
Physical Review B, 2016Co-Authors: Alexis Askitopoulos, Kirill P Kalinin, Timothy Chi Hin Liew, Pasquale Cilibrizzi, Zacharias Hatzopoulos, Pavlos G. Savvidis, Natalia G BerloffAbstract:We investigate the spin dynamics of polariton Condensates spatially separated from and effectively confined by the pumping exciton reservoir. We obtain a strong correlation between the ellipticity of the non-resonant optical pump and the degree of circular polarisation (DCP) of the condensate at the onset of condensation. With increasing excitation density we observe a reversal of the DCP. The spin dynamics of the trapped condensate are described within the framework of the spinor complex Ginzburg-Landau equations in the Josephson regime, where the dynamics of the system are reduced to a current-driven Josephson junction. We show that the observed spin reversal is due to the interplay between an internal Josephson coupling effect and the detuning of the two projections of the spinor condensate via transition from a synchronised to a desynchronised regime. These results suggest that spinor polariton Condensates can be controlled by tuning the non-resonant excitation density offering applications in electrically pumped polariton spin switches.
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nonlinear optical spin hall effect and long range spin transport in polariton lasers
Physical Review Letters, 2012Co-Authors: Elena Kammann, Timothy Chi Hin Liew, Pasquale Cilibrizzi, Zacharias Hatzopoulos, Pavlos G. Savvidis, A. V. Kavokin, Hamid Ohadi, Panayiotis Tsotsis, P G LagoudakisAbstract:We report on the experimental observation of the nonlinear analogue of the optical spin Hall effect under highly nonresonant circularly polarized excitation of an exciton-polariton condensate in a GaAs/AlGaAs microcavity. The circularly polarized polariton Condensates propagate over macroscopic distances, while the collective condensate spins coherently precess around an effective magnetic field in the sample plane performing up to four complete revolutions.
Pascale Senellart - One of the best experts on this subject based on the ideXlab platform.
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Interactions in confined polariton Condensates
Physical Review Letters, 2011Co-Authors: L. Ferrier, Esther Wertz, Reimar Johne, Dmitry Solnyshkov, Pascale Senellart, Aristide Lemaître, Guillaume Malpuech, Jacqueline BlochAbstract:We investigate the effect of interactions in zero-dimensional polariton Condensates. The shape of the condensate wave function is shown to be modified by repulsive interactions with the reservoir of uncondensed excitons. In large micropillar cavities, when uncondensed excitons are located at the center, the condensate is ejected toward the pillar edges. The same effect results in the generation of optical traps in wire cavities. Once polariton Condensates are spatially separated from the excitonic reservoir, spectral signatures of polariton-polariton interactions within the condensate are evidenced.
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spontaneous formation and optical manipulation of extended polariton Condensates
Nature Physics, 2010Co-Authors: Esther Wertz, Reimar Johne, Dmitry Solnyshkov, D. Sanvitto, A. Lemaître, I. Sagnes, Roger Grousson, A. V. Kavokin, Lydie Ferrier, Pascale SenellartAbstract:Long-lived polariton Condensates can propagate well beyond the area of their initial excitation while still maintaining spatial coherence. This enables direct and controllable manipulation of the condensate wavefunction.
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Spontaneous formation and optical manipulation of extended polariton Condensates
Nature Physics, 2010Co-Authors: E. Wertz, L. Ferrier, Reimar Johne, Dmitry Solnyshkov, D. Sanvitto, A. Lemaître, I. Sagnes, Roger Grousson, A. V. Kavokin, Pascale SenellartAbstract:Cavity exciton-polaritons(1,2) (polaritons) are bosonic quasiparticles offering a unique solid-state system for investigating interacting Condensates(3-10). Up to now, disorder-induced localization and short lifetimes(4,6,11) have prevented the establishment of long-range off-diagonal order(12) needed for any quantum manipulation of the condensate wavefunction. In this work, using a wire microcavity with polariton lifetimes much longer than in previous samples, we show that polariton Condensates can propagate over macroscopic distances outside the excitation area, while preserving their spontaneous spatial coherence. An extended condensate wavefunction builds up with a degree of spatial coherence larger than 50% over distances 50 times the polariton de Broglie wavelength. The expansion of the condensate is shown to be governed by the repulsive potential induced by photogenerated excitons within the excitation area. The control of this local potential offers a new and versatile method to manipulate extended polariton Condensates. As an illustration, we demonstrate synchronization of extended Condensates by controlled tunnel coupling(13,14) and localization of Condensates in a trap with optically controlled dimensions.
P G Lagoudakis - One of the best experts on this subject based on the ideXlab platform.
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optical bistability under nonresonant excitation in spinor polariton Condensates
Physical Review Letters, 2018Co-Authors: Lucy Pickup, Alexis Askitopoulos, Kirill P Kalinin, Zacharias Hatzopoulos, Pavlos G. Savvidis, Natalia G Berloff, P G LagoudakisAbstract:: We realize bistability in the spinor of polariton Condensates under nonresonant optical excitation and in the absence of biasing external fields. Numerical modeling of the system using the Ginzburg-Landau equation with an internal Josephson coupling between the two spin components of the condensate qualitatively describes the experimental observations. We demonstrate that polariton spin bistability strongly depends on the condensate's overlap with the exciton reservoir by tuning the excitation geometry and sample temperature. We obtain noncollapsing bistability hysteresis loops for a record range of sweep times, [10 μs, 1 s], offering a promising route to spin switches and spin memory elements.
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nonlinear optical spin hall effect and long range spin transport in polariton lasers
Physical Review Letters, 2012Co-Authors: Elena Kammann, Timothy Chi Hin Liew, Pasquale Cilibrizzi, Zacharias Hatzopoulos, Pavlos G. Savvidis, A. V. Kavokin, Hamid Ohadi, Panayiotis Tsotsis, P G LagoudakisAbstract:We report on the experimental observation of the nonlinear analogue of the optical spin Hall effect under highly nonresonant circularly polarized excitation of an exciton-polariton condensate in a GaAs/AlGaAs microcavity. The circularly polarized polariton Condensates propagate over macroscopic distances, while the collective condensate spins coherently precess around an effective magnetic field in the sample plane performing up to four complete revolutions.