Conceitos gerais sobre o emaranhamento com aplicação em moléculas quânticas

Abstract

From the 90 0 s, quantum teleportation protocols have been increasing the interest on entanglement of bipartite systems, once the implementation of the first demand the use of maximally entangled states. In this work, it is discussed a theoretical proposal of the dynam- ical generation of GHZ state, a kind of an entangled state defined in a three qubit system. The physical scenario for the proposal is a set of six charged quantum dots, divided by pairs. Each pair is coupled by tunneling so defining the quantum molecule. If only one electron in excess is allowed per pair of dots, a qubit can be encoded. Electrons from different qubits interact by Coulomb coupling, opening the possibility of definition of entangled states. The quantum dynamics is explored, by solving the Von Neumann equation for the density matrix. The characterization of the quantum dynamics is made by calculating the population of the electronic states and the fidelity considering a target quantum state. The quantification of the entanglement degree is made by calculating 2-tangle and 3-tangle. Varying the physical pa- rameters of the system of interest, specific conditions for the generation of GHZ are obtained and the state are characterized.