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arXiv · 1707.04756

Orbital degree of freedom in artificial electron lattices on metal surface

Liang Ma·Wen-Xuan Qiu·Jing-Tao Lü·Jin-Hua Gao
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Abstract

Orbital degree of freedom plays a fundamental role in condensed matter physics. Recently, a new kind of artificial electron lattice has been realized in experiments by confining the metal surface electrons with adsorbed molecular lattice. A most recent example is the Lieb lattice realized by CO adsorption on Cu(111) surface [M. R. Slot, et al., Nat. Phys. 13, 672(2017)]. The Lieb lattice is of special interest due to its flat band physics. Here, by first-principles calculations, muffin-tin potential model and tight binding model, we demonstrate that, the high energy states observed in the experiment actually correspond to the artificial $p$-orbitals of the electron lattice. Our numerical results, together with the experimental observation, show that artificial $p$-orbital fermionic lattice has already been realized in solid state system. This opens a new avenue to investigate the orbital degree of freedom in a controllable way.

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Liang Ma, Wen-Xuan Qiu, Jing-Tao Lü, Jin-Hua Gao. 2017-07-15. Orbital degree of freedom in artificial electron lattices on metal surface. https://doi.org/10.1103/physrevb.99.205403

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