Abstract
The symmetry of the superconducting order parameter in quasi-two-dimensional bis-ethylenedithio-tetrathiafulvalene (BEDT-TTF) organic superconductors is a subject of ongoing debate. We report ab initio density-functional-theory calculations for a number of organic superconductors containing κ-type layers. Using projective Wannier functions, we derive the parameters of a common low-energy Hamiltonian based on individual BEDT-TTF molecular orbitals. In a random-phase approximation spin-fluctuation approach, we investigate the evolution of the superconducting pairing symmetry within this model, and we point out a phase transition between extended s+dx2-y2 and dxy symmetry. We discuss the origin of the mixed order parameter and the relation between the realistic molecule description and the widely used dimer approximation. Based on our ab initio calculations, we position the investigated materials in the obtained molecule model phase diagram, and we simulate scanning tunneling spectroscopy experiments for selected cases. Our calculations show that many κ-type materials lie close to the phase-transition line between the two pairing symmetry types found in our calculation, possibly explaining the multitude of contradictory experiments in this field.
| Original language | English |
|---|---|
| Article number | 024515 |
| Journal | Physical Review B |
| Volume | 94 |
| Issue number | 2 |
| DOIs | |
| Publication status | Published - Jul 19 2016 |
| Externally published | Yes |
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ASJC Scopus subject areas
- Condensed Matter Physics
Cite this
Near-degeneracy of extended s+dx2-y2 and dxy order parameters in quasi-two-dimensional organic superconductors. / Guterding, Daniel; Altmeyer, Michaela; Jeschke, Harald Olaf; Valentí, Roser.
In: Physical Review B, Vol. 94, No. 2, 024515, 19.07.2016.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Near-degeneracy of extended s+dx2-y2 and dxy order parameters in quasi-two-dimensional organic superconductors
AU - Guterding, Daniel
AU - Altmeyer, Michaela
AU - Jeschke, Harald Olaf
AU - Valentí, Roser
PY - 2016/7/19
Y1 - 2016/7/19
N2 - The symmetry of the superconducting order parameter in quasi-two-dimensional bis-ethylenedithio-tetrathiafulvalene (BEDT-TTF) organic superconductors is a subject of ongoing debate. We report ab initio density-functional-theory calculations for a number of organic superconductors containing κ-type layers. Using projective Wannier functions, we derive the parameters of a common low-energy Hamiltonian based on individual BEDT-TTF molecular orbitals. In a random-phase approximation spin-fluctuation approach, we investigate the evolution of the superconducting pairing symmetry within this model, and we point out a phase transition between extended s+dx2-y2 and dxy symmetry. We discuss the origin of the mixed order parameter and the relation between the realistic molecule description and the widely used dimer approximation. Based on our ab initio calculations, we position the investigated materials in the obtained molecule model phase diagram, and we simulate scanning tunneling spectroscopy experiments for selected cases. Our calculations show that many κ-type materials lie close to the phase-transition line between the two pairing symmetry types found in our calculation, possibly explaining the multitude of contradictory experiments in this field.
AB - The symmetry of the superconducting order parameter in quasi-two-dimensional bis-ethylenedithio-tetrathiafulvalene (BEDT-TTF) organic superconductors is a subject of ongoing debate. We report ab initio density-functional-theory calculations for a number of organic superconductors containing κ-type layers. Using projective Wannier functions, we derive the parameters of a common low-energy Hamiltonian based on individual BEDT-TTF molecular orbitals. In a random-phase approximation spin-fluctuation approach, we investigate the evolution of the superconducting pairing symmetry within this model, and we point out a phase transition between extended s+dx2-y2 and dxy symmetry. We discuss the origin of the mixed order parameter and the relation between the realistic molecule description and the widely used dimer approximation. Based on our ab initio calculations, we position the investigated materials in the obtained molecule model phase diagram, and we simulate scanning tunneling spectroscopy experiments for selected cases. Our calculations show that many κ-type materials lie close to the phase-transition line between the two pairing symmetry types found in our calculation, possibly explaining the multitude of contradictory experiments in this field.
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UR - http://www.scopus.com/inward/citedby.url?scp=84980396073&partnerID=8YFLogxK
U2 - 10.1103/PhysRevB.94.024515
DO - 10.1103/PhysRevB.94.024515
M3 - Article
AN - SCOPUS:84980396073
VL - 94
JO - Physical Review B
JF - Physical Review B
SN - 2469-9950
IS - 2
M1 - 024515
ER -