Fermi surface of LaSb2 and direct observation of a CDW transition

Abstract

We have studied the temperature-dependent electronic structure of the light rare-earth antimonide LaSb2 by combining angle-resolved photoemission (ARPES) measurements and density functional theory (DFT) calculations. ARPES measurements show the appearance of band replicas in the low-temperature Fermi surface with q = 0.25 ± 0.02 A−1 and a band folding of the same periodicity with a considerable spectral weight in the folded band. From our calculations we elucidate that the folded band exhibiting the new periodicity is associated with the La-Sb layer. We propose that an in-plane distortion, probably affecting the whole unit cell, is the structural modification related to the electronic changes. All these results converge to support that a charge density wave is stabilized in LaSb2 at low temperature.