Electron-boson spectral density of LiFeAs obtained from optical data.
J Phys Condens Matter
; 27(5): 055701, 2015 Feb 11.
Article
in En
| MEDLINE
| ID: mdl-25612554
ABSTRACT
We analyze existing optical data in the superconducting state of LiFeAs at T = 4 K, to recover its electron-boson spectral density. A maximum entropy technique is employed to extract the spectral density I(2)χ(ω) from the optical scattering rate. Care is taken to properly account for elastic impurity scattering which can importantly affect the optics in an s-wave superconductor, but does not eliminate the boson structure. We find a robust peak in I(2)χ(ω) centered about Ω(R) â
8.0 meV or 5.3 k(B)Tc (with Tc = 17.6 K). Its position in energy agrees well with a similar structure seen in scanning tunneling spectroscopy (STS). There is also a peak in the inelastic neutron scattering (INS) data at this same energy. This peak is found to persist in the normal state at T = 23 K. There is evidence that the superconducting gap is anisotropic as was also found in low temperature angular resolved photoemission (ARPES) data.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Language:
En
Journal:
J Phys Condens Matter
Journal subject:
BIOFISICA
Year:
2015
Document type:
Article