Zobrazeno 1 - 10
of 418
pro vyhledávání: '"Pittalis S."'
Publikováno v:
Eur. Phys. J. B (2018) 91: 173
Ab initio calculations of the magnon dispersion in ferromagnetic materials typically rely on the adiabatic local density approximation (ALDA) in which the effective exchange-correlation field is everywhere parallel to the magnetization. These calcula
Externí odkaz:
http://arxiv.org/abs/1804.04556
A semi-relativistic density-functional theory that includes spin-orbit couplings and Zeeman fields on equal footing with the electromagnetic potentials, is an appealing framework to develop a unified first-principles computational approach for non-co
Externí odkaz:
http://arxiv.org/abs/1704.07304
Publikováno v:
Phys. Rev. B 91, 075109 (2015)
We investigate the effects of inhomogeneities on spin entanglement in many-electron systems from an ab-initio approach. The key quantity in our approach is the local spin entanglement length, which is derived from the local concurrence of the electro
Externí odkaz:
http://arxiv.org/abs/1409.0363
We construct a generalized-gradient approximation for the exchange-energy density of finite two-dimensional systems. Guided by non-empirical principles, we include the proper small-gradient limit and the proper tail for the exchange-hole potential. T
Externí odkaz:
http://arxiv.org/abs/1403.6297
Publikováno v:
Phys. Rev. B 88, 245102 (2013)
We derive the gradient expansion for the exchange energy of a spin-polarized electron gas by perturbing the uniformly spin polarized state and thus inducing a small non-collinearity that is slowly varying in space. We show that the exchange-energy co
Externí odkaz:
http://arxiv.org/abs/1309.4905
Publikováno v:
Phys. Rev. Lett. 108, 246803 (2012)
Recent advances in the creation and modulation of graphene-like systems are introducing a science of "designer Dirac materials". In its original definition, artificial graphene is a man-made nanostructure that consists of identical potential wells (q
Externí odkaz:
http://arxiv.org/abs/1201.1734
Publikováno v:
Phys. Rev. B 87, 035144 (2013)
We derive a self-consistent local variant of the Thomas-Fermi approximation for (quasi-)two-dimensional (2D) systems by localizing the Hartree term. The scheme results in an explicit orbital-free representation of the electron density and energy in t
Externí odkaz:
http://arxiv.org/abs/1111.6470
Publikováno v:
Phys. Rev. B 84, 245118 (2011)
We extend a recent formulation of quantum continuum mechanics [J. Tao et. al, Phys. Rev. Lett. {\bf 103}, 086401 (2009)] to many-body systems subjected to a magnetic field. To accomplish this, we propose a modified Lagrangian approach, in which motio
Externí odkaz:
http://arxiv.org/abs/1109.3644
Autor:
Sanna, A., Pittalis, S., Dewhurst, J. K., Monni, M., Sharma, S., Ummarino, G., Massidda, S., Gross, E. K. U.
We study the graphite intercalated compound CaC$_6$ by means of Eliashberg theory, focusing on the anisotropy properties. An analysis of the electron-phonon coupling is performed, and we define a minimal 6-band anisotropy structure. Comparing with Su
Externí odkaz:
http://arxiv.org/abs/1108.2800
Autor:
Pittalis, S., Rasanen, E.
Publikováno v:
Phys. Rev. B 82, 165123 (2010)
In modeling low-dimensional electronic nanostructures, the evaluation of the electron-electron interaction is a challenging task. Here we present an accurate and practical density-functional approach to the two-dimensional many-electron problem. In p
Externí odkaz:
http://arxiv.org/abs/1009.4292