Entanglement controlled single - electron transmittivity

We show that the electron transmittivity of single electrons propagating along a one-dimensional (1D) wire in the presence of two magnetic impurities is affected by the entanglement between the impurity spins. For suitable values of the electron wave vector, there are two maximally entangled spin states which, respectively, make the wire completely transparent whatever the electron spin state or strongly inhibit electron transmission. The key role that entanglement plays not only in most quantum information processing tasks [1] but also in a broad range of physical processes such as quantum transport [2]–[4] has been considerably clarified over the past few years. In this paper, we illustrate the interplay between entanglement and single-electron transport properties in a one-dimensional (1D) wire in the presence of two scattering magnetic impurities. Such a system is the electron analogue of a Fabry–Perot (FP) interferometer [5], with the two impurities playing the role of two mirrors with a quantum degree of freedom: the spin. This suggests the interesting question of whether 5 Author to whom any correspondence should be addressed.