title: Charge-density wave condensate in charge-ordered manganites: impact of ferromagnetic order and spin-glass disorder.
abstract: The behavior of charge-density wave (CDW) condensates with the systematic introduction of ferromagnetic (FM) and spin-glass phases in the charge-ordered (CO) lattice of Nd(0.5)Sr(0.5)MnO(3) (NSMO) and Eu(0.5)Sr(0.5)MnO(3) (ESMO) epitaxial thin films was investigated by terahertz time-domain spectroscopy. The optical conductivity of (100)-oriented NSMO film, in which the CO lattice has an insignificant volume of the FM phase, exhibits a peak with attributes of CDW collective excitation at ~3.2 meV. This peak becomes completely submerged in the Drude continuum as the volume of the epitaxial strain-induced FM phase increases in the CO state of (110)- and (111)-oriented NSMO films. In contrast, the ESMO (100) film, having a short-range CO phase amid a spin-glass-like state, displays a subtle CDW peak in conductivity. Modeling the optical terahertz conductivity with the phenomenological Lorentz-Drude relation and extracting the optical weight due to both contributions (Lorentz and Drude), it was found that the manifestation of CDW condensates is associated with the generic strength of charge ordering and that the condensate suffers a more pronounced suppression when FM order dilutes the CO lattice than when spin-glass disorder weakens the CO state.
authors: Indian Institute of Science Education and Research (IISER) Bhopal, MP-462023, India.
authors: Rakesh
authors: R
authors: Rana
authors: Nilesh
authors: N
authors: Awari
authors: Parul
authors: P
authors: Pandey
authors: Abhishek
authors: A
authors: Singh
authors: S S
authors: SS
authors: Prabhu
authors: D S
authors: DS
authors: Rana