Polariton-polariton interactions in microcavities under a resonant 10 to 100 picosecond pulse excitation

Abstract

Experimental studies have been performed of the nonequilibrium transitions in multistable cavity-polariton systems under 10 ps long pulsed excitation, i.e., within nearly the shortest time scale necessary for the multistability to be revealed in GaAs-based microcavities. The experiments were aimed to determine the ratio of the strengths of the pair interactions between polaritons with parallel and antiparallel spins, which also was the question raised in a number of recent studies. We show that in contrast to the cases of continuous-wave or nanosecond long pumping conditions, in the fast pulse regime the system is not affected by the excitonic reservoir. The interaction between polaritons with opposite spins is definitely attractive at a nearly zero detuning of exciton and photon modes; as a result, optical response can be essentially multistable at a linearly polarized excitation. With increasing pulse duration up to 100 ps, the reservoir can start manifesting itself in a reduction of the spin multistability.

Nonlinear route to intrinsic Josephson oscillations in spinor cavity-polariton condensates

“…Thus, at the pulse tail, we deal with a freely decaying rather than pumped polariton condensate. It only can be slightly fed by a long-lived excitonic reservoir excited when the pump was strong [23,29,37,38]; however, this effect cannot be pronounced in our system where the pump is comparatively short term and acts far below the exciton level.…”

“…The polariton-polariton interaction is spin sensitive. Normally, polaritons with opposite spins are nearly uncoupled, but polaritons with the same spins strongly repel each other so that the condensate level experiences a blueshift that can largely exceed its linewidth [16][17][18][19][20][21][22][23][24]. The difference in the interaction strengths of same-and opposite-spin polaritons results in the multistability under resonant and coherent driving [25][26][27][28][29][30][31][32].…”

Blowup dynamics of coherently driven polariton condensates: Experiment

“…Such a system bears two steady-state branches under a circularly polarized pump when only one of the two polariton spin components is excited. This is the case discussed in our current study; note, however, that in a general case, polariton condensates can exhibit a richer multistable behavior due to the spin anisotropy of the polariton-polariton interaction [3,21].…”

Динамика спинорной экситон-поляритонной системы в латерально сжатых GaAs микрорезонаторах при резонансном фотовозбуждении

“…Большинство иссле-дований поляритонных конденсатов с использованием резонансного фотовозбуждения до сих пор проводи-лось с использованием импульсов с длительностью, значительно превышающей время жизни поляритонов. В этих условиях свойства конденсата контролируют-ся возбуждающим светом, а конденсат демонстриру-ет мультистабильное поведение [19][20][21][22], обусловленное обратной связью в конденсате со спин-анизотропным поляритон-поляритонным взаимодействием между ам-плитудой и эффективной резонансной частотой поля в МР [23,24]. Переключения между стационарными состояниями вблизи точек бифуркации сопровождаются резкими скачками напряженности поля и поляризации и приводят к таким явлениям как оптические пара-метрические осцилляции [25,26], поляритонные солито-ны [27][28][29], спиновые кольца [20,30] и т. д.…”