Limits...
Purely one-dimensional bands with a giant spin-orbit splitting: Pb nanoribbons on Si(553) surface

View Article: PubMed Central - PubMed

ABSTRACT

We report on a giant Rashba type splitting of metallic bands observed in one-dimensional structures prepared on a vicinal silicon substrate. A single layer of Pb on Si(553) orders this vicinal surface making perfectly regular distribution of monatomic steps. Although there is only one layer of Pb, the system reveals very strong metallic and purely one-dimensional character, which manifests itself in multiple surface state bands crossing the Fermi level in the direction parallel to the step edges and a small band gap in the perpendicular direction. As shown by spin-polarized photoemission and density functional theory calculations these surface state bands are spin-polarized and completely decoupled from the rest of the system. The experimentally observed spin splitting of 0.6 eV at room temperature is the largest found to now in the silicon-based metallic nanostructures, which makes the considered system a promising candidate for application in spintronic devices.

No MeSH data available.


Calculated electronic structure of Si(553)-Pb.Band structure of Si(553)-Pb calculated with  = 3.37 Å (a,b). The oppositely polarized bands are indicated by the red and blue circles. A diameter of the circles determines a value of the corresponding component of the polarization vector. (c) Direction of the polarization vector of three pairs of bands determined at EB = 0.09 eV. The inset in (a) presents a part of 1D bands which are of interest for the determination of the polarization vector direction shown in (c). The number in each diagram denotes corresponding band indicated in the inset of (a).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC5382770&req=5

f5: Calculated electronic structure of Si(553)-Pb.Band structure of Si(553)-Pb calculated with  = 3.37 Å (a,b). The oppositely polarized bands are indicated by the red and blue circles. A diameter of the circles determines a value of the corresponding component of the polarization vector. (c) Direction of the polarization vector of three pairs of bands determined at EB = 0.09 eV. The inset in (a) presents a part of 1D bands which are of interest for the determination of the polarization vector direction shown in (c). The number in each diagram denotes corresponding band indicated in the inset of (a).

Mentions: According to the DFT calculations the surface Pb bands are split, and the splitting originates from the spin-orbit interaction. Interestingly, the polarization vectors have both in-plane, Fig. 5(a), and out-of-plane, Fig. 5(b), components, similar as in the experiment (see Fig. 4). A potential gradient along the direction perpendicular to the surface is responsible for the appearance of the in-plane component of the polarization vector. On the other hand, the Pb-row-projected electron states located in different parts of Brillouin zone are responsible for the asymmetry in partial charge distribution within the surface, thus for the out-of-plane spin polarization component.


Purely one-dimensional bands with a giant spin-orbit splitting: Pb nanoribbons on Si(553) surface
Calculated electronic structure of Si(553)-Pb.Band structure of Si(553)-Pb calculated with  = 3.37 Å (a,b). The oppositely polarized bands are indicated by the red and blue circles. A diameter of the circles determines a value of the corresponding component of the polarization vector. (c) Direction of the polarization vector of three pairs of bands determined at EB = 0.09 eV. The inset in (a) presents a part of 1D bands which are of interest for the determination of the polarization vector direction shown in (c). The number in each diagram denotes corresponding band indicated in the inset of (a).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC5382770&req=5

f5: Calculated electronic structure of Si(553)-Pb.Band structure of Si(553)-Pb calculated with  = 3.37 Å (a,b). The oppositely polarized bands are indicated by the red and blue circles. A diameter of the circles determines a value of the corresponding component of the polarization vector. (c) Direction of the polarization vector of three pairs of bands determined at EB = 0.09 eV. The inset in (a) presents a part of 1D bands which are of interest for the determination of the polarization vector direction shown in (c). The number in each diagram denotes corresponding band indicated in the inset of (a).
Mentions: According to the DFT calculations the surface Pb bands are split, and the splitting originates from the spin-orbit interaction. Interestingly, the polarization vectors have both in-plane, Fig. 5(a), and out-of-plane, Fig. 5(b), components, similar as in the experiment (see Fig. 4). A potential gradient along the direction perpendicular to the surface is responsible for the appearance of the in-plane component of the polarization vector. On the other hand, the Pb-row-projected electron states located in different parts of Brillouin zone are responsible for the asymmetry in partial charge distribution within the surface, thus for the out-of-plane spin polarization component.

View Article: PubMed Central - PubMed

ABSTRACT

We report on a giant Rashba type splitting of metallic bands observed in one-dimensional structures prepared on a vicinal silicon substrate. A single layer of Pb on Si(553) orders this vicinal surface making perfectly regular distribution of monatomic steps. Although there is only one layer of Pb, the system reveals very strong metallic and purely one-dimensional character, which manifests itself in multiple surface state bands crossing the Fermi level in the direction parallel to the step edges and a small band gap in the perpendicular direction. As shown by spin-polarized photoemission and density functional theory calculations these surface state bands are spin-polarized and completely decoupled from the rest of the system. The experimentally observed spin splitting of 0.6 eV at room temperature is the largest found to now in the silicon-based metallic nanostructures, which makes the considered system a promising candidate for application in spintronic devices.

No MeSH data available.