Ferromagnetism

Abstract

S 1. I N T R O D U C T I O N H E magnetic and associated properties of substances which behave magnetically like iron have long provided a happy hunting ground if not for the T '' smoother pebble than ordinary'' at least for the more curiously shapedone.

Two-dimensional lateral GaN/SiC heterostructures: First-principles studies of electronic and magnetic properties

“…The presence of spin splitting in a similar system, AlN/SiC, was observed in Ref. 21, where it was explained as the result of the Stoner instability 42,43 . The Stoner criterion 42,43 states that a spin splitting happens at high enough DOS.…”

“…21, where it was explained as the result of the Stoner instability 42,43 . The Stoner criterion 42,43 states that a spin splitting happens at high enough DOS. To clearly observe why the spin splitting occurs at certain interfaces, we perform a spin-unpolarized calculation and project the DOS onto all interfaces, as shown in Fig.…”

Polarization of a quasi-two-dimensional repulsive Fermi gas with Rashba spin-orbit coupling: A variational study

“…This choice leads to a clear distinction between spin up (n ↑ ) and spin down (n ↓ ) particle densities, and at any given value of g the HF energy per volume can thus be expressed as a function of these quantities: E(n ↑ ,n ↓ ). A minimization of this function at fixed total density n = n ↑ + n ↓ , leads to zero polarization (n ↑ = n ↓ ) for g below the critical value g c = π/m, and full polarization (either n = n ↑ or n = n ↓ ) at g > g c 56]). …”

Critical Behavior of a Strongly Interacting 2D Electron System

“…The behavior of strongly interacting electrons in two dimensions is a forefront area of condensed matter physics in which theoretical methods are still poorly developed and new experimental results are of great interest. Consistent with Fermi liquid theory at high electron densities [1], these two-dimensional (2D) systems are expected to undergo one or more transitions to spatially and/or spinordered phases as the density is decreased, ultimately forming a Wigner crystal in the dilute, strongly interacting limit [2][3][4][5][6]. The interaction strength is characterized by the ratio of the Coulomb energy to the Fermi energy, determined by the dimensionless parameter r s ¼ 1=ðn s a 2 B Þ 1=2 (here n s is the areal density of electrons, a B ¼ "@ 2 =m b e 2 , and ", e, and m b are the dielectric constant, the absolute value of the electron charge, and the band mass, respectively); the parameter r s is proportional to n À1=2 s and increases with decreasing electron density, reaching values in excess of r s * 10 in systems investigated experimentally to date.…”