Spin-polarized standing waves at an electronically matched interface detected by Fermi-surface photoemission

Abstract

Highly spin-polarized reflection at an interface of a ferromagnetic thin film is made visible by photoelectron spectroscopy. The technique of k-space mapping of the exchange-split Fermi surface is employed to detect standing waves confined to the ferromagnetic layer. A drastic spin asymmetry of this effect is achieved for a specific matching of the Fermi-surface topologies of film and substrate, respectively. For Fe͑110͒ films on a W substrate, intense standing waves are obtained exclusively for majority states, while minority states are virtually unaffected by the boundary.

Quantized electronic fine structure with large anisotropy in ferromagnetic Fe films

“…(a) shows the experimental Fermi surface close to the Γ-point for 22 ML Fe/W(110) as determined by ARPES. The data show the presence of a diamond-shaped outer structure and an additional inner fine structure which could not be observed in previous ARPES experiments [21]. The fine structure consists of parallel, almost straight lines along ΓN in accordance with the vanishing dispersion observed for this direction.…”

“…With increasing film thickness the binding energies of all states successively shift towards the Fermi level. This electronic fine structure close to E F could not be observed in previous experiments on Fe/W(110) [21]. An overview of all measured binding energies in the investigated thickness range is given in Fig.…”

Large amplitude oscillation of magnetic anisotropy engineered by substrate step density

“…4 In particular, quantum well states ͑QWS͒ can be formed in ferromagnetic ͑FM͒ thin films. 6 QWS can modulate the electronic structure at the Fermi level and alter the magnetic anisotropy strongly 7 as it has been shown experimentally for Fe films grown on a stepped Ag͑1,1,10͒ surface. 4 As a consequence, the magnetic anisotropy and easy magnetization axis oscillate as a function of film thickness.…”

Quark number susceptibilities from two-loop hard thermal loop perturbation theory

“…In addition, it was also argued recently that the QNS may be used to identify the position of the critical end point in the QCD phase diagram [5]. The QNS have been extensively studied in the last two decades using a variety of approaches including perturbative QCD (pQCD) [3,[6][7][8], lattice QCD (LQCD) simulations [9,[11][12][13][14][15][16][17][18], Nambu-Jona-Lasinio (NJL) models [4,19,20], Polyakov Loop-Nambu-Jona-Lasinio (PNJL) models [20][21][22][23], hard-thermal/dense-loop (HTL/HDL) resummation techniques [24][25][26][27][28][29], rainbow-ladder and beyond-rainbow-ladder approximations of the Dyson-Schwinger equations [30], strong-coupling techniques [31], functional renormalisation group techniques [32], and quasiparticle models [33].…”