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F. M. Guedes

Publications and source records attributed to F. M. Guedes.

3 recordsLinked to original sources

Bell-CHSH inequality and unitary transformations in Quantum Field Theory

Unitary transformations are employed to enhance the violations of the Bell-CHSH inequality in relativistic Quantum Field Theory. The case of the scalar field in $1+1$ Minkowski space-time is scrutinized by relying on the Tomita-Takesaki modular theory. The example of the bounded Hermitian operator $sign(φ(f))$, where $φ(f)$ stands for the smeared scalar field, is worked out. It is shown that unitary deformations enable for violations of the Bell-CHSH inequality. The setup is generalized to the Proca vector field by means of its equivalence with the scalar theory.

quant-ph

A study of the spin 1 Unruh-De Witt detectors

A study of the spin 1 Unruh-De Witt detectors interacting with a relativistic scalar quantum field is presented. After tracing out the field modes, the resulting density matrix for a bipartite qutrit system is employed to investigate the violation of the Bell-CHSH inequality. Unlike the case of spin $1/2$, for which the effects of the quantum field result in a decreasing of the size of violation, in the case of spin $1$ both decreasing and increasing of the violation may occur. This effect is ascribed to the fact that Tsirelson's bound is not saturated in the case of qutrits.

hep-th