Coupling the spatial and polarization degrees of freedom of light - applications in measurement theory and open quantum systems

Álvarez Velásquez, Juan Rafael

Daniel F. Urrego, Jiŕí Svozilík, Mayerlin Nuñez +1 more

Coupling light spatial variables and its polarization, we report an all-optical experiment in which we implement a dephasing channel and generate Markovian and non-Markovian dynamics by environment engineering via spatial interference of light.

Keh Pann

Malena O. Hor-Meyll, J. O. de Almeida, Gabriela Barreto Lemos +2 more

We report an experiment in which the moments of spatial coordinates are measured in down-converted photons directly, without having to reconstruct any marginal probability distributions. We use a spatial light modulator to couple the spatial degrees of freedom and the polarization of the fields, which acts as an ancilla system. Information about the spatial correlations is obtained via measurements on the ancilla qubit. Among other applications, this new method provides a more efficient technique to identify continuous variable entanglement.

Daniel F. Urrego, Juan-Rafael Álvarez, Omar Calderón-Losada +3 more

We present the experimental implementation and theoretical model of a controllable dephasing quantum channel using photonic systems. The channel is implemented by coupling the polarization and the spatial distribution of light that play, in the perspective of open quantum systems, the role of quantum system and environment, respectively. The capability of controlling our channel allows us to visualize its effects in a quantum system. Different from standard dephasing channels, our channel presents an exotic behavior in the sense that the evolution of a state, from a pure to a mixed state, shows an oscillatory behavior if tracked in the Bloch sphere. Additionally, we report the evolution of the purity and perform a quantum process tomography to obtain the χ matrix associated to our channel.