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Atomic-scale visualization of surface-assisted orbital order.

ABSTRACT: Orbital-related physics attracts growing interest in condensed matter research, but direct real-space access of the orbital degree of freedom is challenging. We report a first, real-space, imaging of a surface-assisted orbital ordered structure on a cobalt-terminated surface of the well-studied heavy fermion compound CeCoIn5. Within small tip-sample distances, the cobalt atoms on a cleaved (001) surface take on dumbbell shapes alternatingly aligned in the [100] and [010] directions in scanning tunneling microscopy topographies. First-principles calculations reveal that this structure is a consequence of the staggered d xz -d yz orbital order triggered by enhanced on-site Coulomb interaction at the surface. This so far overlooked surface-assisted orbital ordering may prevail in transition metal oxides, heavy fermion superconductors, and other materials.

SUBMITTER: Kim H

PROVIDER: S-EPMC5609848 | biostudies-other | 2017 Sep

REPOSITORIES: biostudies-other

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Atomic-scale visualization of surface-assisted orbital order.

Kim Howon H Yoshida Yasuo Y Lee Chi-Cheng CC Chang Tay-Rong TR Jeng Horng-Tay HT Lin Hsin H Haga Yoshinori Y Fisk Zachary Z Hasegawa Yukio Y

Science advances 20170922 9

Orbital-related physics attracts growing interest in condensed matter research, but direct real-space access of the orbital degree of freedom is challenging. We report a first, real-space, imaging of a surface-assisted orbital ordered structure on a cobalt-terminated surface of the well-studied heavy fermion compound CeCoIn<sub>5</sub>. Within small tip-sample distances, the cobalt atoms on a cleaved (001) surface take on dumbbell shapes alternatingly aligned in the [100] and [010] directions in ...[more]

PMID: 28948229

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