Optical Bistability in Electrically Driven Polariton Condensates

Abstract

We observe a bistability in an electrically driven polariton condensate, which is manifested by a memory dependent threshold characteristic. In contrast to the polariton bistabilities previously observed in resonantly optically pumped microcavities, our effect occurs under nonresonant electric pumping and is triggered by the current injection scheme. We explain the origin of the bistability by a dependence of the electron-hole tunneling lifetime on the carrier density in the embedded quantum wells. The field screening effect creates a positive feedback loop, which yields the bistable behavior of the condensate. We develop a rate-equation-based model which qualitatively explains the occurrence of the hysteresis under current injection, its reduction with increased magnetic field, and the absence of bistability under optical pumping.

Electro-optical switching between polariton and cavity lasing in an InGaAs quantum well microcavity

“…Further general information on the formation of polariton condensates can for example be found in [20]. Details on the relaxation pathway in this structure will be published elsewhere [21]. All experiments were performed at a temperature of 6K.…”

Optical Bistability under Nonresonant Excitation in Spinor Polariton Condensates

“…It has been observed in systems such as cold atoms [3], lasers [4], self-electro-optic effect devices (SEED) [5] and Fabry-Pérot cavities containing nonlinear materials [6,7]. Optical bistability in microcavity polaritons, the bosonic quasi-particles formed by the strong coupling of cavity photons and excitons, was previously demonstrated for resonant/quasi-resonant optical excitation [8][9][10][11][12][13], electrical biasing [14,15] and nonresonant electrical injection [16]. In resonantly pumped microcavity polaritons, bistability was described by a Kerr-like nonlinearity resulting from polariton-polariton interactions [9] and by employing an analogy with optical parametric oscillators [10].…”

“…In resonantly pumped microcavity polaritons, bistability was described by a Kerr-like nonlinearity resulting from polariton-polariton interactions [9] and by employing an analogy with optical parametric oscillators [10]. Under electrical injection, bistability was observed in the photoluminescence intensity, in the presence of an external magnetic field, and was attributed to the electrostatic screening of the injected charge carriers forming a positive feedback for the backward sweep of the driving current [16].…”

Observation of the Transition from Lasing Driven by a Bosonic to a Fermionic Reservoir in a GaAs Quantum Well Microcavity

“…The density of free carriers 𝑛 𝑒ℎ can be generally described, i.e. in strong as well as weak coupling regimes, by a rate equation 𝑑𝑛 𝑒ℎ 𝑑𝑡 ⁄ = 𝑃 − 𝛾𝑛 𝑒ℎ 11, 24,25 where 𝑃 is the pump rate and 𝛾 the loss rate. In the steady state 7…”