Multipartite quantum eraser in cavity QED

Abstract

We propose a feasible experiment in the context of cavity QED as follows: The initial state is a maximally entangled two cavity mode (M A , M B ). Next a sequence of atoms are sent, one at a time, and interact with mode M B . We show that the which-way information is initially stored only in M B is now distributed among the parties of the global system. The results realize known complementarity relations derived in the context of arbitrary qubits. We show that this dynamics may lead to a quantum eraser phenomenon provided that measurements of the probe atoms are performed in a basis which maximizes the visibility.

Maximizing Complementary Quantities by Projective Measurements

“…In Ref. [25], the authors studied a similar maximization procedure, although only for the visibility V (n,M) q A . In order to produce a multipartite quantum eraser, the coefficients α i and β i were chosen to obtain an increase in the visibility, maintaining a standard value for the coupling parameter (gT = 2π).…”

“…In that case, visibility and predictability increases, and entanglement decreases, since the measurements are made in order to establish the quantum eraser. In Reference [25] only the maximization of the visibility was considered, in the present work we extend the analysis and consider maximization of predictability, visibility and concurrence. Also, in the previous work [25], only one value of the coupling constant was considered.…”

“…In Reference [25] only the maximization of the visibility was considered, in the present work we extend the analysis and consider maximization of predictability, visibility and concurrence. Also, in the previous work [25], only one value of the coupling constant was considered. In this contribution we consider a second coupling regime that allows for the comparison between stronger and weaker interactions.…”

“…In this contribution we consider a second coupling regime that allows for the comparison between stronger and weaker interactions. Some questions may arise from the analysis presented in [25]: how is the behavior of the visibility, predictability and Entanglement, for different strengths of the coupling between the cavities and the N atoms? Is there any difference in this behavior if one measure the qubits in order to maximize another complementarity quantity?…”

“…Thus, part R is able to control which complementarity quantity of part A they (A and R) would like to maximize. For instance, if A and R desire that q A is in a superposition state, R can choose which basis he/she will project each qubit in order to accomplish the task (quantum eraser task [25]). However, now R and A are able to choose another complementarity quantity: if they would like to obtain and/or maintain an Entangled state between A and B, R may project each q i in a basis chosen in order obtain an state nearly maximally Entangled (the same idea follows for the predictability).…”