Influência da polarização e do ambiente nos aspectos complementares da natureza quântica da luz

Abstract

Although the wave-particle duality is not a relatively new concept in modern physics, the interest in it remains an important point of study and investigation. Attributing mutually exclusive behaviors of a quantum system to the experimental apparatus to which it is subjected, in the example of a two-path interferometer, the wave and particle aspects are quantified through the visibility of the interference fringes and information about the path taken by the particles. In this work, we use quantum information theoretical tools to derive two quantities that measure the wave and particle aspects in the scenario of the Young’s double slit experiment for a photon system. The derivation of these quantities was based on the formalism of the unified density matrix of coherence and polarization, which allowed us to obtain quantifiers capable of describing the combined influence of the path taken by the photons, as well as the polarization. It is possible to verify that these quantifiers obey a complementarity relation analogous to the EGY inequality, whose validity is tested through some examples with pure and mixed quantum states. By extending the study of wave-particle duality to open systems, we confront the reality of the decoherence effect. Though it plays a fundamental role in the study of the quantum-to-classical transition, for quantum systems the decoherence effect acts as an obstacle to quantum information processing. We show here that quantifiers can be useful for investigating in which ways the environment in question interferes in the loss of quantum information encoded in the photons and the consequences of the types of environments used for information processing.