Kondo effect of a Co atom on Cu(111) in contact with an iron tip

Abstract

Single Co atoms, which exhibit a Kondo effect on Cu(111), are contacted with Cu and Fe tips in a low-temperature scanning tunneling microscope. With Fe tips, the Kondo effect persists with the Abrikosov-Suhl resonance significantly broadened. In contrast, for Cu-covered W tips, the resonance width remains almost constant throughout the tunneling and contact ranges. The distinct changes of the line width are interpreted in terms of modifications of the Co d state occupation owing to hybridization with the tip apex atoms.

Non-Zeeman splitting for a spin-resolved STM with a Kondo adatom in a spin-polarized two-dimensional electron gas

“…34,45,47,49,50 Here, we highlight the experiment done by Kawahara et al, 49 where the measured LDOS shows that one spin channel has a Kondo peak pinned at the vicinity of the host Fermi level, while the opposite is shifted by the spin polarization of the 2DEG forming the island surface. We note that the behavior we see here is not similar to the usual Zeeman splitting due to an external magnetic field.…”

Dimensionality effects in the local density of states of ferromagnetic hosts probed via STM: Spin-polarized quantum beats and spin filtering

“…(24) as well as in the transport polarization of Eq. (25). Such an effect is due to interference between the slightly different Fermi wave numbers k F ↑ and k F ↓ [Eq.…”

“…24 In the condensed-matter literature on scanning microscopy, there is a profusion of work discussing spin-dependent phenomena employing ferromagnetic leads coupled to quantum dots or adatoms in the Kondo regime. 4,6,7,[25][26][27][28][29][30][31][32][33][34][35][36][37][38][39][40][41][42][43][44] Here, we mention those with metallic samples and buried impurities in which the anisotropy of the Fermi surface plays an important role in electron tunneling. [45][46][47][48][49][50] According to the experiment of Prüser et al, 45 such anisotropy allows atoms of Fe and Co beneath the Cu(100) surface to scatter electrons in preferential directions of the material due to an effect called "electron focusing."…”

Spin-dependent beating patterns in thermoelectric properties: Filtering the carriers of the heat flux in a Kondo adatom system

“…Additionally, novel effects are manifested in the presence of ferromagnetic leads [14][15][16][17][18][19][20][21][22][23][24][25][26] and long spin-relaxation time [27,28] when thermoelectric properties become spin dependent. In this case, the spin degeneracy of the chemical potentials is lifted and the phenomenon known as spin accumulation arises, thus affecting the behavior of the thermoelectric quantities.…”