Entanglement, which is one of the stranger features of quantum mechanics, is now seen as a resource that can be exploited for teleportation of quantum states and secure distribution of cryptographic keys. In addition, it is thought of as one of the main reasons that quantum information devices may be able to outperform their classical counterparts. In this respect, many solid state systems have merit as quantum information processors, for example, quantum dots. However, exactly modeling solid state many-body systems is often computationally intractable; hence, approximations are used. We present methods of calculating the spatial entanglement of an interacting electron system within the framework of density-functional theory [1]. These methods are tested on a model quantum dot system (3-dimensional Hooke\'s atom) and on one-dimensional systems with tailored densities [2]. We analyze how the strength of the confining potential affects the spatial entanglement and how accurately the methods that we introduced reproduce the exact trends.
[1] J.P. Coe, A. Sudbery and I. D\'Amico, Phys. Rev. B 77, 205122 (2008) [2] J. P. Coe, I. D\'Amico, arXiv:0905.4645