Realistic modeling of the electronic structure and the effect of correlations for Sn/Si(111) and Sn/Ge(111) surfaces

Schuwalow, Sergej; Grieger, Daniel; Lechermann, Frank

doi:10.1103/physrevb.82.035116

Cited by 26 publications

(47 citation statements)

References 53 publications

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“…5. Here, adatoms occupy the T 4 positions in Si/Si(111), Sn/Si(111) and Pb/Si(111), 6,9 while in the case of the C/Si(111) adatoms are in the S 4 underlayer positions.…”

Section: Results Of Dft+so Calculationsmentioning

confidence: 99%

“…• Néel order is indeed stabilized in the Si(111):Sn system, 2,9 while other studies based on the DMFT approach argued that an unusual collinear row-wise (RW) alignment takes place and emerges from long-range electron hopping processes. 7,8 Generally, a geometrically frustrated arrangement may destroy any long-range magnetic configuration and give rise to a spin liquid state.…”

Section: Hartree-fock Simulations Of the Electronic Modelsmentioning

confidence: 90%

“…At the moment there is no consistent description of the magnetic ground state as well as of the excited states at finite temperatures and magnetic fields. For instance, first-principles simulations 9 of the adatom system with Sn revealed that the 120…”

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confidence: 99%

“…6,9,20 . Band structures calculated within DFT demonstrate the main peculiarity of the systems that is one wellseparated doubly-degenerate band located near the Fermi level, which is further split when spin-orbit coupling (DFT+SO) is taken into account (Fig.2b).…”

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confidence: 99%

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Spin-orbit coupling and magnetic interactions in Si(111):{C,Si,Sn,Pb}

et al. 2016

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We study the magnetic properties of the adatom systems on a semiconductor surface Si(111):{C,Si,Sn,Pb} -(On the basis of all-electron density functional theory calculations we construct effective low-energy models taking into account spin-orbit coupling and electronic correlations. In the ground state the surface nanostructures are found to be insulators with the non-collinear 120• Néel (for C, Si, Sn monolayer coverages) and 120• row-wise (for Pb adatom) antiferromagnetic orderings. The corresponding spin Hamiltonians with anisotropic exchange interactions are derived by means of the superexchange theory and the calculated Dzyaloshinskii-Moriya interactions are revealed to be very strong and compatible with the isotropic exchange couplings in the systems with Sn and Pb adatoms. To simulate the excited magnetic states we solve the constructed spin models by means of the Monte Carlo method. At low temperatures and zero magnetic field we observe complex spin spiral patterns in Sn/Si(111) and Pb/Si(111). On this basis the formation of antiferromagnetic skyrmion lattice states in adatom sp electron systems in strong magnetic fields is discussed.

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“…5. Here, adatoms occupy the T 4 positions in Si/Si(111), Sn/Si(111) and Pb/Si(111), 6,9 while in the case of the C/Si(111) adatoms are in the S 4 underlayer positions.…”

Section: Results Of Dft+so Calculationsmentioning

confidence: 99%

Section: Hartree-fock Simulations Of the Electronic Modelsmentioning

confidence: 90%

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confidence: 99%

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confidence: 99%

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Spin-orbit coupling and magnetic interactions in Si(111):{C,Si,Sn,Pb}

et al. 2016

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“…Commonly considered to be realizations of the one-band Hubbard model and toy systems for investigating many-body physics on the triangular lattice, such surfaces have been explored experimentally [2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18] and theoretically [19][20][21][22][23][24][25][26][27][28][29][30][31].These so-called α-phases show a remarkable variety of interesting physics including commensurate charge density wave (CDW) states [5,6,9] and isostructural metal to insulator transitions (MIT) [14]. However, while specific systems and/or phenomena have been investigated also theoretically, a comprehensive understanding including materials trends is still lacking.…”

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confidence: 99%

Long-Range Coulomb Interactions in Surface Systems: A First-Principles Description within Self-Consistently CombinedGWand Dynamical Mean-Field Theory

Hansmann

Ayral²,

Vaugier³

et al. 2013

Phys. Rev. Lett.

117

162

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Systems of adatoms on semiconductor surfaces display competing ground states and exotic spectral properties typical of two-dimensional correlated electron materials which are dominated by a complex interplay of spin and charge degrees of freedom. We report a fully ab initio derivation of low energy Hamiltonians for the adatom systems Si(111):X, with X=Sn, Si, C, Pb, that we solve within self-consistent combined GW and dynamical mean field theory ("GW+DMFT"). Calculated photoemission spectra are in agreement with available experimental data. We rationalize experimentally observed tendencies from Mott physics towards charge-ordering along the series as resulting from substantial long-range interactions.PACS numbers: 71.15. Mb, 73.20.At, 71.10.Fd, 71.30.h Understanding the electronic properties of materials with strong electronic Coulomb correlations remains one of the biggest challenges of modern condensed matter physics. The interplay of delocalization and interactions is not only at the origin of exotic ground states, but also determines the excitation spectra of correlated materials. The "standard model" of correlated fermions, the Hubbard model, in principle captures these phenomena. Yet, relating the model to the material on a microscopic footing remains a challenge. Even more importantly, the approximation of purely local Coulomb interactions can become severe in realistic materials, where long-range interactions and charge fluctuation physics cannot be neglected.Systems of adatoms on semiconducting surfaces, such as Si (111):X with X=Sn, C, Si, Pb, have been suggested [1] to be good candidates for observing low-dimensional correlated physics. Commonly considered to be realizations of the one-band Hubbard model and toy systems for investigating many-body physics on the triangular lattice, such surfaces have been explored experimentally [2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18] and theoretically [19][20][21][22][23][24][25][26][27][28][29][30][31].These so-called α-phases show a remarkable variety of interesting physics including commensurate charge density wave (CDW) states [5,6,9] and isostructural metal to insulator transitions (MIT) [14]. However, while specific systems and/or phenomena have been investigated also theoretically, a comprehensive understanding including materials trends is still lacking. A central goal of our work is to present a unified picture that relates, within a single framework, different materials (adatom systems), placing them in a common phase diagram.We derive low-energy effective Hamiltonians ab initio from a combined density functional and constrained random phase approximation (cRPA) scheme [32] in the implementation of [33] (see also the extension to surface systems in [34]). While the first surprise are the relatively large values of the onsite interactions which we find to be of the order of the bandwidth (≈ 1 eV), most importantly we show that non-local interactions are large (nearestneighbor interaction of ≈ 0.5 eV) and, hence, an essential part of t...

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