Quantum and Classical Aspects of Coherence.

Parker, MC, P. Thornton Greenland, Boyd, RW

Sarangam Majumdar, Sukla Pal

In this article, we anticipate the effect of quantum coherence in quorum sensing mechanism. Theoretical and experimental physics have come a long way since the emergence of human civilization. In the beginning of the early twentieth century scientists discovered quantum physics to understand the deeper aspects of nature going beyond the classical physics. Now-adays the areas of research in quantum mechanics are being driven by a shared goal to harness and exploit quantum coherence and entanglement

Vandana Arora, Jagneet Kaur Anand

While coherence is an intrinsic characteristic of quantum systems, de-coherence describes the environmental intrusion during the measurement process, leading to transition from quantum to classical reality, hence playing a pivotal role in quantum information processing. The authors emphasize the need to understand physical aspect of various elements of the density matrix of a quantum state and how these elements control the coherence/decoherence behaviour of quantum physics and the transition to classical domain

Lili Wang, Zhengli Chen, Wenhua Wang +1 more

Gerard Lachs

Previous work of this contract on the waveshape aspects of light from a classical point of view led to an interest to investigate the quantum mechanical aspects of the waveshape of light. This work contains some results of this investigation. One of the results obtained is an upper bound on the channel capacity where the only noise in the channel is due to the zero point field. The P-representation of a general state in terms of the coherent states is utilized to obtain the probability densities of the in-phase component, quadrature component, envelope, and the number of photons of the field. This is done for thermal radiation and for radiation which is a mixture of thermal radiation and coherent radiation with the result that the thermal radiation behaves as pure Gaussian noise while the coherent radiation behaves as a classical signal. The quantum mechanical formalism is utilized to obtain the rules of superposition for a large class of fields. The results show that the signal part can be treated classically and the noise part is nearly the same as would be found from the classical superposition of noise.

José Tito Mendonça, Hugo Terças