Figure 1

(a),(b) STM and STS measurements, respectively, obtained with a clean W tip on Fe(001) covered with 7.2 ML Mn at 370 K. (a) A topographic image obtained at a set point of $V_S=-0.5\mathrm{V}$, $I=0.5\mathrm{n}\mathrm{A}$. Scan size is $\mathrm{150}\mathrm{\times }\mathrm{100}\mathrm{n}{\mathrm{m}}^{\mathrm{2}}$. (b) The $dI/dV$ map at $+0.2\mathrm{V}$ measured at the same area as (a). (c),(e) SP-STM and (d),(f) SP-STS measurements obtained with Fe-coated tips. (c),(e) Topographic images obtained at a set point of $V_S=-0.5\mathrm{V}$, $I=0.5\mathrm{n}\mathrm{A}$. Scan size is $\mathrm{100}\mathrm{\times }\mathrm{67}\mathrm{n}{\mathrm{m}}^{\mathrm{2}}$ for (c) and $\mathrm{14}\mathrm{\times }\mathrm{20}\mathrm{n}{\mathrm{m}}^{\mathrm{2}}$ for (e). (e) A hidden Fe step [7], where step height is only 0.02 nm and magnetizations are reversed. (d),(f) The $dI/dV$ map at $+0.2\mathrm{V}$ measured at the same area as (c) and (e), respectively. For (d) black-white scale ranges from 0.75 nA/V to $1.00\mathrm{n}\mathrm{A}/\mathrm{V}$. In (f), one pixel is 0.25 nm. (g) The line profile along the white line in (f).Reuse & Permissions

Figure 2

(a),(b) $dI/dV$ curves normalized by the voltage-dependent tunneling probability functions, which were obtained on Mn films thicker than three layers with clean W tips and Fe-coated tips, respectively. Solid and dotted curves are the $dI/dV$ and the $(dI/dV)/T$ curves, respectively. Tunneling probability functions (dashed curves) were obtained by a fit to the $dI/dV$ curves. In (b), black and grey curves are representative of the odd and the even layers, respectively.Reuse & Permissions

Figure 3

(a) Band structure of an eight-layer Mn(001) slab. The plot shows both “majority” and “minority” bands, which are equivalent for this even-layered antiferromagnetically ordered slab. The magnetization for each layer is defined by the difference in integrated local DOS of the “majority” and “minority” bands. Thick lines indicate $d_{z^2}$-like states around $\overline{\mathrm{\Gamma }}$, and the dashed line the Fermi level. $\alpha$, $\beta$, and $\gamma$ could contribute to the experimentally observed $+0.8\mathrm{V}$ peak. (b),(c) The isocharge density distributions of the $\alpha$ and the $\beta$ states at $\overline{\mathrm{\Gamma }}$ in a (110) plane. Dots and dashed lines indicate atom positions and the boundary between vacuum and bulk, respectively.Reuse & Permissions

Figure 4

(a),(b) SP-STS measurements representative of the even (grey curve) and the odd layers (black curve) $>3\mathrm{M}\mathrm{L}$) at negative- $V_S=-0.5\mathrm{V}$, $I=0.5\mathrm{n}\mathrm{A}$) and positive-voltage set points ($V_S=+0.5\mathrm{V}$, $I=0.5\mathrm{n}\mathrm{A}$), respectively. (c) The asymmetry in the $dI/dV$ curves. Dotted and solid curves are obtained from (a) and (b), respectively. (d) The asymmetry in the normalized even and odd layer $(dI/dV)/T$ curves with respect to the sample bias voltage. Open circles and triangles were obtained with the same Fe-coated tip using negative and positive voltage set points, respectively. Solid dots were obtained with a different Fe-coated tip ($V_S=-0.5\mathrm{V}$). The black solid curve is obtained from the calculated spin-dependent DOS.Reuse & Permissions