Bell states and entanglement dynamics on two coupled quantum molecules

Abstract

This work provides a complete description of entanglement properties between electrons inside coupled quantum molecules, nanoestructures which consist of two quantum dots. Each electron can tunnel between the two quantum dots inside the molecule, being also coupled by Coulomb interaction. First, it is shown that Bell states act as a natural basis for the description of this physical system, defining the characteristics of the energy spectrum and the eigenstates. Then, the entanglement properties of the eigenstates are discussed, shedding light on the roles of each physical parameters on experimental setup. Finally, a detailed analysis of the dynamics shows the path to generate states with a high degree of entanglement, as well as physical conditions associated with coherent oscillations between separable and Bell states.

Quantum entanglement driven by electron-vibrational mode coupling

“…If δ ± = 0, it seems that the states with electronic part being |Ψ− D and |Φ− D are decoupled, at the same time that |Ψ+ D and |Φ+ D are not, in the same way that in Ref. 66. Nevertheless, if elements for the first two lines on matrix (A2), associated with |Ψ − , 00 and |Φ − , 00 respectively, are written using the notation | | we obtain:…”

“…The first matrix resembles the rotated matrix on Bell basis, whose properties discussed in details on Ref. 66, and the matrices G v depends on g v and carry on the effect of electron-vibrational mode coupling, where the factor √ N v appears on the specific elements of the matrix (A2) which depends on the values of N v of the coupled subspaces.…”

Lindblad formalism based on fermion-to-qubit mapping for nonequilibrium open quantum systems

“…Our goal is to check the quantum dynamics at the specific condition for generation of maximally entangled states [35]. We start solving numerically Eq.…”

“…(20), is shown in Fig. 3, considering the physical parameters used to obtain maximally entangled states [35]. For the sake of comparison, we include in the inset the evolution of the same quantities when the probe is turned off, considering a shorter time scale.…”

“…The periodic coherent dynamics from Ref. [35] is recovered from our approach, where a Bell state is dynamically generate at the times when P |1001 = P |0110 = 0.5, while P |1010 = P |0101 = 0. When the probe is turned on, as a current passes through the narrow conduction channel in dot 5, the effect is to induce an attenuation of the coherent oscillations of populations P |1001 and P |0110 , black and red lines on Fig.…”