Quantum Information Science attracts considerable attention owing to its fundamental character, on the one hand, since information is physical, meaning that physical systems are needed to store, process, and transmit it; and, on the other hand, to the potential technological applications. Since present-day computing is based on binary logic, it is natural to search for extensions in discrete quantum systems, containing only two levels, the so-called quantum bits, or qubits. There is, nevertheless, a growing interest in the use of continuous variable systems, typically in Quantum Optics, because techniques for creation and detection of non-classical states of light are well-known and mastered. Our group is among the few in Brazil to work on continuous variable systems, especially from the experimental viewpoint. We have studied the interaction of light with coherently prepared atomic media in the framework of Electromagnetically Induced Transparency, EIT. We have also studied entanglement between the bright beams produced by an Optical Parametric Oscillator (OPO). In the next four years, we expect to perform a series of experiments, mainly to: study a quantum key distribution protocol, using the entangled twin beams from the OPO; implement quantum teleportation with color conversion, by using the (frequency) nondegenerate twin beams (this is already funded, in a project awarded to Prof. Marcelo Martinelli; no supplementary funding is requested for this investigation here); study the recently generated pump-signal-idler tripartite entanglement in the OPO; study the phenomenon of "entanglement sudden death" in continuous variable systems, recently discovered by us; use the tripartite entanglement for quantum information tasks, such as communications; observe non-classical properties of light, such as squeezing and entanglement, by interaction with coherently prepared atomic media; investigate, both theoretically and experimentally, ways to exchange quantum information between atomic systems and bright light beams, bringing together these two general research subjects. (AU)
Articles published in Agência FAPESP Newsletter about the research grant:
MUNOZ-MARTINEZ, LUIS F.;
SILVA BARBOSA, FELIPPE ALEXANDRE;
COELHO, ANTONIO SALES;
VILLAR, ALESSANDRO S.
Exploring six modes of an optical parametric oscillator.
Physical Review A,
AUG 13 2018.
Web of Science Citations: 1.