Transmission of entangled photons studied by quantum tomography: do we need plasmonic resonances?

Abstract

We performed quantum tomography to reveal the robustness of quantum correlations of photons entangled in polarisation after their interaction with plasmonic and nonplasmonic environments at normal incidence. The experimental findings clearly show that the visibility of quantum correlations survives the interaction, and that the presence of plasmonic resonances has not any significant influence on the survival of polarisation correlations for transmitted photon pairs. The results indicate that quantum states can be encoded into the multiple motions of a many-body electronic system without demolishing their quantum nature. The plasmonic structures and their resonances only enhance the overall transmission. Thus, they could benefit the pair detection rate, that is the number of coincidences per unit of time, but they do not affect the visibility of quantum correlations. We also performed quantum tomography of the entangled pairs after interaction with the continuous planar gold film as a function of the incidence angle. The latter illustrates the loss of polarization correlations that arises from the partially polarizing properties of the isotropic sample out of normal incidence. Our work shows that plasmonic structures are not needed to exploit quantum entanglement if the rate of coincidence counting is sufficient.

Probing a Hybrid Channel for the Dynamics of Non-Local Features

“…Additionally, the impact of various parameters such as the anisotropy, spin coupling strength, DM and KSEA interactions, as well as external noise parameters of the static noise was studied. Utilizing the NG, EU, LC, and EN functions given in Equations ( 13), ( 14), (16), and ( 17), we explored the dynamics of entanglement, quantum memory, coherence, and entropy in the spin system. All the functions were evaluated for the final density matrix obtained in Equation (12).…”

“…Besides, various studies have focused on providing schemes and critical studies on improving the degree of quantum correlations between the sub-systems of the non-local states considering various procedures (for example, see Refs. [16][17][18]), therefore giving rise to the successful implementation of the quantum protocols. In addition, the information encoded in qubits can be processed more quickly and with less processing power because of the quantum entanglement phenomenon.…”