Multipartite polariton entanglement in semiconductor microcavities

Abstract

We study the entanglement of multiple polariton modes, which results in continuous variable cluster states suitable for quantum computation. Schemes are based on parametric scattering between spin-polarized lower and upper polariton branches in planar microcavities or spin-polarized orbital angular momentum states in mesa structures. Such systems are modeled by numerical solution of truncated density matrices and compared to the solution of the Heisenberg equations for the set of field correlators up to third order. Four-body entanglement is evidenced by violation of the van Loock-Furusawa quadripartite inequalities. We show that the entanglement is able to withstand a realistic strength of pure dephasing present in typical systems.

Production of Colored Pigments with Amorphous Arrays of Black and White Colloidal Particles

“…For very thin membranes, the thickness was found to affect the appearance of the color: a distinct color was observed for membranes thinner than approximately 0.05 mm, whereas the color appeared whiter for a thicker membrane. The reflectance peak was considered to originate from wavelength-specific constructive interference, [16,17] and its angle independency implied that the silica particles formed an amorphous array with only short-range order. Figure 1 c shows the transmission spectra of a membrane composed of 360 nm-sized silica particles.…”

Dynamics of bipartite and tripartite entanglement in a dissipative system of continuous variables

“…For example, a recent effort was focused upon entanglement generation from two remote microscopic systems with no direct interactions, which was said to be realized with the assistance of a bosonic bath [12]. On the other hand, technological breakthroughs in quantum optics has renewed interest in the basic subject of entanglement [13,14,15,16]. For example, the polariton, an entity mixing light and matter, can be a suitable vehicle for experimental realization of CV entanglement.…”

“…For example, the polariton, an entity mixing light and matter, can be a suitable vehicle for experimental realization of CV entanglement. In particular, Liew and Savona [16] extensively studied the bipartite and multipartite entanglement between polariton modes with the consideration of parametric scattering as an effective interaction among the modes. Thanks to both parametric scattering and repulsive potential induced by the exciton reservoir and the pump field, a strong coupling microcavity in the form of a ZnO whispering gallery structure, was demonstrated to achieve a polariton condensate at room temperature [17,18,19].…”

Reservoir-induced decoherence of resonantly excited confined polaritons

“…In recent years, there has been an increasing number of proposals to use microcavity polaritons as a source of single photons [2,3], entangled photons [4][5][6][7][8], and as quantum computing devices [9][10][11][12]. On the one hand, the interest for using polaritons lies in their peculiar dispersion that weakens phonon scattering [13][14][15][16] or their ability to overcome dephasing by increasing the number of particles in the condensate [9,11].…”