92 citations · 1.3k across the 98 of their papers we have counts for
10 papers · 1 filter
Aspects of the competition between atom-field and field-environment couplings under the influence of an external source in dispersive Jaynes-Cummings model
J. G. Peixoto de Faria, M. C. Nemes
We give a fully description of the dynamics of an atom dispersively coupled to a field mode in a dissipative environment fed by an external source. The competition between the unit…
Renormalization Conditions and the Sliding Scale in the Implicit Regularization Scheme: A Simple Connection
A. Brizola, S. R. Gobira, Marcos Sampaio +1
We describe in detail how a sliding scale is introduced in the renormalization of a QFT according to integer-dimensional implicit regularization scheme. We show that since no regul…
Analysing a complementarity experiment on the quantum-classical boundary
M. O. Terra Cunha, M. C. Nemes
The complementarity experiment reported in Bertet [{\it{et al.}} (2001), {\it{Nature}} {\bf{411}}, 166.] is discussed. The role played by entanglement in reaching the classical lim…
Tunneling Rate for Superparamagnetic Particles by the Instanton Method
E. H. Martins Ferreira, M. C. Nemes
We derive the tunneling rate for paramagnetic molecules in the context of a collective spin model. By means of path integral methods an analytical expression is derived. Given the…
Phases of quantum states in completely positive non-unitary evolution
J. G. Peixoto de Faria, A. F. R. de Toledo Piza, M. C. Nemes
We define an operational notion of phases in interferometry for a quantum system undergoing a completely positive non-unitary evolution. This definition is based on the concepts of…
Comparing Implicit, Differential, Dimensional and BPHZ Renormalisation
M. Sampaio, A. P. Baeta Scarpelli, B. Hiller +3
We compare a momentum space implicit regularisation (IR) framework with other renormalisation methods which may be applied to dimension specific theories, namely Differential Renor…
Decoherence Sturdy Memories in the Presence of Quantum Dissipation
K. M. Fonseca Romero, S. G. Mokarzel, M. C. Nemes
We consider N identical oscillators coupled to a single environment and show that the conditions for the existence of decoherence free subspaces are degeneracy of the oscillator fr…
Stern-Gerlach Entanglement in Spinor Bose-Einstein Condensates
S. Cruz-Barrios, M. C. Nemes, A. F. R. de Toledo Piza
Entanglement of spin and position variables produced by spatially inhomogeneous magnetic fields of Stern-Gerlach type acting on spinor Bose-Einstein condensates may lead to interfe…
Exact Description of Decoherence in Optical Cavities
K. M. Fonseca Romero, M. C. Nemes
The exact reduced dynamics for the independent oscillator model in the RWA approximation at zero and finite temperatures is derived. It is shown that the information about the inte…
Sensitivity to Initial Conditions in Quantum Dynamics: an Analytical Semiclassical Expansion
K. M. Fonseca-Romero, M. C. Nemes, J. G. Peixoto de Faria +1
We construct a class of systems for which quantum dynamics can be expanded around a mean field approximation with essentially classical content. The modulus of the quantum overlap…