Abstract
We revisit the problem that relevant parts of band structures for a given cell choice can reflect exact or approximate higher symmetries of subsystems in the cell and can therefore be significantly simplified by an unfolding procedure that recovers the higher symmetry. We show that band-structure unfolding can be understood as projection onto induced irreducible representations of a group obtained by extending the original group of translations with a number of additional symmetry operations. The resulting framework allows us to define a generalized unfolding procedure that includes the point group operations and can be applied to any quantity in the reciprocal space. The unfolding of the Brillouin zone follows naturally from the properties of the induced irreducible representations. In this context, we also introduce a procedure to derive tight-binding models of reduced dimensionality by making use of point group symmetries. Further, we show that careful consideration of unfolding has important consequences on the interpretation of angle-resolved photoemission experiments. Finally, we apply the unfolding procedure to various representative examples of Fe-based superconductor compounds and show that the one-iron picture arises as an irreducible representation of the glide-reflection group, and we comment on the consequences for the interpretation of one-iron versus two-iron Brillouin zone representations.
| Original language | English |
|---|---|
| Article number | 195121 |
| Journal | Physical Review B - Condensed Matter and Materials Physics |
| Volume | 90 |
| Issue number | 19 |
| DOIs | |
| Publication status | Published - Nov 12 2014 |
| Externally published | Yes |
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ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
Cite this
Unfolding of electronic structure through induced representations of space groups : Application to Fe-based superconductors. / Tomić, Milan; Jeschke, Harald Olaf; Valentí, Roser.
In: Physical Review B - Condensed Matter and Materials Physics, Vol. 90, No. 19, 195121, 12.11.2014.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Unfolding of electronic structure through induced representations of space groups
T2 - Application to Fe-based superconductors
AU - Tomić, Milan
AU - Jeschke, Harald Olaf
AU - Valentí, Roser
PY - 2014/11/12
Y1 - 2014/11/12
N2 - We revisit the problem that relevant parts of band structures for a given cell choice can reflect exact or approximate higher symmetries of subsystems in the cell and can therefore be significantly simplified by an unfolding procedure that recovers the higher symmetry. We show that band-structure unfolding can be understood as projection onto induced irreducible representations of a group obtained by extending the original group of translations with a number of additional symmetry operations. The resulting framework allows us to define a generalized unfolding procedure that includes the point group operations and can be applied to any quantity in the reciprocal space. The unfolding of the Brillouin zone follows naturally from the properties of the induced irreducible representations. In this context, we also introduce a procedure to derive tight-binding models of reduced dimensionality by making use of point group symmetries. Further, we show that careful consideration of unfolding has important consequences on the interpretation of angle-resolved photoemission experiments. Finally, we apply the unfolding procedure to various representative examples of Fe-based superconductor compounds and show that the one-iron picture arises as an irreducible representation of the glide-reflection group, and we comment on the consequences for the interpretation of one-iron versus two-iron Brillouin zone representations.
AB - We revisit the problem that relevant parts of band structures for a given cell choice can reflect exact or approximate higher symmetries of subsystems in the cell and can therefore be significantly simplified by an unfolding procedure that recovers the higher symmetry. We show that band-structure unfolding can be understood as projection onto induced irreducible representations of a group obtained by extending the original group of translations with a number of additional symmetry operations. The resulting framework allows us to define a generalized unfolding procedure that includes the point group operations and can be applied to any quantity in the reciprocal space. The unfolding of the Brillouin zone follows naturally from the properties of the induced irreducible representations. In this context, we also introduce a procedure to derive tight-binding models of reduced dimensionality by making use of point group symmetries. Further, we show that careful consideration of unfolding has important consequences on the interpretation of angle-resolved photoemission experiments. Finally, we apply the unfolding procedure to various representative examples of Fe-based superconductor compounds and show that the one-iron picture arises as an irreducible representation of the glide-reflection group, and we comment on the consequences for the interpretation of one-iron versus two-iron Brillouin zone representations.
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U2 - 10.1103/PhysRevB.90.195121
DO - 10.1103/PhysRevB.90.195121
M3 - Article
AN - SCOPUS:84911418101
VL - 90
JO - Physical Review B-Condensed Matter
JF - Physical Review B-Condensed Matter
SN - 1098-0121
IS - 19
M1 - 195121
ER -