A team composed of scientists from the National Synchrotron Radiation Centre SOLARIS, the Institute of Physics of the Jagiellonian University, the Institute of Nuclear Physics of the Polish Academy of Sciences (PAN), and the Institute of Low Temperature and Structure Research of the Polish Academy of Sciences (PAN), has published the results of their research on the superconducting compound LaCuSb2. The experiment was conducted using the URANOS beamline at the SOLARIS synchrotron.
In the studies conducted on LaCuSb2, a material from the RTSb2 family (where R is a rare earth metal and T is a transition metal), interesting properties of its electronic structure were identified. This material is a superconductor with a transition temperature of approximately 0.9 K. To investigate its electronic structure, angle-resolved photoemission spectroscopy (ARPES) and density functional theory (DFT) calculations were employed.
The analysis of the Fermi surface and energy bands of LaCuSb2 revealed the presence of linear dispersion relations corresponding to Dirac dispersions and nodal lines along the M–A and X–R directions. The Fermi surface of LaCuSb2 is composed of four branches, with two inner branches having a more three-dimensional character. A significant finding was that the Fermi surface nesting in LaCuSb2 is stronger than in the related material LaAgSb2. Despite this, no charge density waves (CDW) were observed in LaCuSb2, but they are present in LaAgSb2, what makes an interesting contrast between these two compounds.
Read more on SOLARIS website
Image: Electronic structure of LaCuSb2 along the “X” ̅”-” “Γ” ̅”-” “X” ̅ direction, collected using 66 and 54 eV with LH and LV light polarizations. Green arrows indicate linear bands, and red arrows indicate Dirac-like band crossings. Calculated surface spectra for La-Sb and Sb terminations, using the surface Green function technique, are presented for comparison.