We show that the appropriate on-off switching of Josephson coupling between exciton-polaritons in coupled semiconductor microcavities can reveal the full capacity for generating entanglement with a recently proposed method which essentially enhances the nonlinearity of the system. The improvement achieved with this simple modulation of the coupling is substantial over the case where it is kept constant. We also show that even better results can be obtained with the additional on-off switching of the enhanced nonlinearity. The suggested procedure is expected to find also application in other research areas, where nonlinear interacting bosons are encountered.
We show that the appropriate on-off switching of Josephson coupling between exciton-polaritons in coupled semiconductor microcavities can reveal the full capacity for generating entanglement with a recently proposed method which essentially enhances the nonlinearity of the system. The improvement achieved with this simple modulation of the coupling is substantial over the case where it is kept constant. We also show that even better results can be obtained with the additional on-off switching of the enhanced nonlinearity. The suggested procedure is expected to find also application in other research areas, where nonlinear interacting bosons are encountered.
Creating sufficiently strong entanglement between exciton-polaritons is a step of utmost importance towards the exploitation of these systems in quantum information processing with continuous variables. The generation of entanglement relies on the strength of the nonlinearity, which is weak for semiconductor microcavities. Recently, a way to essentially amplify the nonlinearity strength in these systems using two coherent laser fields was suggested, leading in theory to the creation of a fair amount of entanglement between exciton-polaritons in coupled cavities and networks in general. Throughout this process, the Josephson coupling and the enhanced nonlinearity in the two coupled cavities are held constant, with the former always larger. In this work we show that the entanglement generated with the above procedure can be substantially enhanced with the appropriate on-off switching of Josephson coupling between the cavities. Furthermore, we show that if we consider a time-dependent enhanced nonlinearity, through the modulation of the corresponding coherent laser fields, and allow it to attain larger values than the Josephson coupling, then we can generate larger values of entanglement using shortcuts to adiabaticity, a method developed to accelerate quantum adiabatic dynamics. The suggested methodologies are not restricted to exciton-polaritons but are expected to find applications in a wide spectrum of physical contexts, where nonlinear interacting bosons are encountered.
We use shortcuts to adiabaticity, a method introduced to speed up adiabatic quantum dynamics, for the efficient generation of entanglement between exciton-polaritons in coupled semiconductor microcavities. A substantial improvement is achieved, compared to a recently proposed method that essentially enhances the nonlinearity of the system. Our method takes advantage of a time-dependent nonlinearity, which can become larger than the Josephson coupling between the cavities, while the conventional method is restricted to a constant nonlinearity lower than the coupling. The suggested procedure is expected to also find application in other research areas in optics, where nonlinear interacting bosons are encountered.
Nonlinear optical response of cavity polaritons formed in high-g semiconductor microcavities has attracted much attention because of their potential applications to entangled-photon sources and other quantum information technologies. Theoretical ideas of entangled-photon generation, e.g., biexcitonic cavity quantum electrodynamics and polariton-polariton scattering, have been suggested, however these theories are limited in scope of target because they restrict two-exciton states to either biexciton or unbound two-exciton states. As for exciton system with small binding energy of biexciton, it is likely that the interplay between the biexciton and unbound two-exciton states have much impact on generation efficiency of entangled photons. The authors introduces a general model including both biexciton and unbound two-exciton states and discuss generation efficiency of entangled photons.
We provide a systemic theory to entangle excitons with microcavity photons. This is realized by adopting an exciton-optomechanics system and introducing a nonlinear dispersive interaction with a mechanical oscillator. We show that when either the exciton and cavity modes in the weak-coupling regime, or the two exciton-polariton modes in the strong-coupling regime are, respectively, resonant with the optomechanical Stokes and anti-Stokes sidebands, entanglement between excitons and cavity photons, or between two exciton polaritons, can be established. The entanglement is in the steady state and can potentially be achievable at room temperature. In both cases, genuine tripartite entanglement is shown to be present. Published by the American Physical Society 2024
Semiconductor microcavities have great potential for quantum information science, quantum optics, and quantum sensing. Researchers designing devices based on these microcavities could benefit from having accurate figures of merit to guide their design and enhance the entanglement latency and strength of their devices. This article presents a closed formula for computing the exciton-photon concurrence in semiconductor microcavities. The formula is tailored for the ultralow density limit of both excitons and photons, allowing a better understanding of the entanglement properties in this regime. The closed formula allows for accurate and easy quantification of the exciton-photon coupling strength in terms of the parameters of the system like the couplings, frequencies, and linewidths, which has applications in quantum optics and quantum information science. The presented formulas can be used in rational microcavity design for various applications, such as single-photon sources, quantum light sources, and optoelectronic devices. This contributes to the systematic design and control of entanglement properties of quantum devices tailored for specific tasks in quantum information science, quantum optics, and quantum sensing. In summary, this work represents a valuable contribution to both practical applications and fundamental research in the fields of nanostructures, quantum optics, and quantum information science.
We show experimentally optical bistability and the existence of bright and dark resonator solitons in the strong coupling regime between quantum-well excitons and the optical field in a semiconductor microcavity. The strong coupling results in a quasi-particle exciton-polariton, which gives access to positive and negative reactive and dissipative optical nonlinearities, as opposed to the usual room temperature semiconductor nonlinearities possessing essentially only one sign. The existence range and the properties of solitons can be varied widely by the detuning between polariton states and light frequency.