Sum rules for the exchange-correlation energy functional of the extended constrained-search theory: Application to checking the validity of the vorticity expansion approximation of the current-density functional theory

2010

Phys. Rev. B

We present a computational pair density ͑PD͒ functional theory using multiple Slater determinants in constructing the PD. Compared to the effective initial scheme ͓M. Higuchi and K. Higuchi, Phys. Rev. B 78, 125101 ͑2008͔͒, the search region for the ground-state PD is substantially extended within the set of N-representable PDs. The merit of the present scheme is to guarantee the resultant PD to be N-representable and to describe correlation effects beyond the effective initial scheme, which enables us to tackle with the development of the approximate form of the kinetic energy functional. We derive two restrictive conditions on the kinetic energy functional. With the aid of these restrictive conditions, we also propose several types of approximate functionals of the kinetic energy. To check the abilities and limitations of the present scheme including such approximate functionals, actual calculations are performed for the neutral neon atom. The results show that the present scheme provides the N-representable and correlated PDs, though it would have some limitations. What we need to do first for improvement of the computational PD functional theory is that the development of the approximate functional of the kinetic energy is further advanced along the present scheme.

Section: Restrictive Conditions On the Kinetic Energy Functionalmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Computational pair density functional theory: A proposal for the kinetic energy functional

2010

Phys. Rev. B

“…The approximate form of the xc energy functional in the original DFT or its extensions has been successfully developed using relations to be fulfilled by the xc energy functional as the restrictive conditions [51][52][53][54][55]. For instance, the generalized gradient approximation [51][52][53] for the xc energy functional of the DFT and the vorticity expansion approximation for the xc energy functional of the CDFT [54,55] have been developed so far. Therefore, equation (50) may be used to devise an approximate form of y y j F n, , , .…”

Section: Condition For the Exchange-correlation Energy Functionalmentioning

confidence: 99%

Current-density functional theory for bosonic superfluids

Aizawa

2023

J. Phys. Commun.

A finite-temperature current-density functional theory for superfluids (sf-CDFT) in the thermal equilibrium state is proposed herein. In the sf-CDFT, hydrodynamic physical quantities, such as particle number density, current density, and the order parameter of the Bose–Einstein condensation, are chosen as the basic variables. This theory enables the simultaneous reproduction of the particle number and current densities of both the superfluid and normal fluid components with incorporating effects of the interaction between these components. Specifically, these components are determined by solving two single-particle equations, i.e., the Gross–Pitaevskii–Kohn–Sham and Kohn–Sham equations. Furthermore, using the continuity equation of superfluids, we present the sum rule for the exchange-correlation energy functional of the sf-CDFT, which is useful for developing the approximate form.

“…We comment briefly on the second of the two kinds of magnetic moments (the first being the spin magnetic moment) that electrons in metals primarily possess, the orbital magnetic moment [24][25][26][27][28][29][30][31]. The orbital magnetic moment generally appears when an external magnetic field is applied to metals.…”

Section: Lus Hosmentioning

confidence: 99%

Reduction of g-factor due to Rashba effect in graphene

Shrestha

Journal of Applied Physics

Yoshida

et al. 2021

Graphene is a highly promising material in the field of spin electronics. Recent experiments on electron spin resonance have observed a reduction in the g-factor of graphene. In this paper, we focus on the Rashba effect, which is caused by the work function existing near the surface of graphene. The Rashba effect tilts the spin magnetic moment to the in-plane direction of the graphene sheet, potentially reducing the g-factor. We evaluate this reduction using a simple model system incorporating the Rashba and spin Zeeman effects. We then demonstrate that the resultant g-factor is in close agreement with that observed in the prior experiments, indicating that the Rashba effect is able to account for the remaining reduction in the g-factor of graphene.