Quantum complementarity of microcavity polaritons

We present an experiment that probes polariton quantum correlations by exploiting quantum complementarity. Specifically, we find that polaritons in two distinct idler-modes interfere if and only if they share the same signal-mode so that "which-way" information cannot be gathered. The experimental results prove the existence of polariton pair correlations that store the "which-way" information. This interpretation is confirmed by a theoretical analysis of the measured interference visibility in terms of quantum Langevin equations

Coupled quantum-classical transport in silicon nanowires

We present an extended hydrodynamic model describing the transport of electrons in the axial direction of a silicon nanowire. This model has been formulated by closing the moment system derived from the Boltzmann equation on the basis of the maximum entropy principle of Extended Thermodynamics, coupled to the Schr¨odinger-Poisson system. Explicit closure relations for the high-order fluxes and the production terms are obtained without any fitting procedure, including scattering of electrons with acoustic and non polar optical phonons. We derive, using this model, the electron mobility

A statistical enhancement method for Direct Simulation Monte Carlo in semiconductor devices

The Multicomb variance reduction technique has been introduced in the Direct Simulation Monte Carlo for submicrometric semiconductors. We have implemented the method in a silicon diode n+ − n − n+ and demonstrated its effectiveness. The steady-state statistical error and the figures of merit are obtained. The results of the simulations indicate that the method can enhance the high-energy distribution tail with a good accuracy

Spontaneous Conversion from Virtual to Real Photons in the Ultrastrong Coupling Regime

We show that a spontaneous release of virtual photon pairs can occur in a quantum optical system in the ultrastrong coupling regime. In this regime, which is attracting interest both in semiconductor and superconducting systems, the light-matter coupling rate {\Omega}R becomes comparable to the bare resonance frequency of photons {\omega}0. In contrast to the dynamical Casimir effect and other pair creation mechanisms, this phenomenon does not require external forces or time dependent parameters in the Hamiltonian.Comment: To appear on Phys. Rev. Let