Interplay of phonons, intertwined density waves, and induced spin density wave in trilayer nickelates Pr4-xLaxNi3O10
Authors
Sonia Deswal, Dibyata Rout, Nirmalya Jana, Koushik Pal, Surjeet Singh, Pradeep Kumar
Categories
Abstract
Lattice degrees of freedom (DoF) play a central role in correlated electron systems, strongly influencing the dynamics of the underlying charge carriers and spin excitations. In nickelates, understanding the role of lattice is essential to unravel the interplay between charge, orbital, and spin degree of freedom in giving rise to various emergent phenomena reported recently. Here, we investigate the phononic DoF in a series of trilayer nickelates, namely Pr4-xLaxNi3O10 (where x = 0, 0.4, 1, 2, 3.6, and 4) using temperature and polarization dependent Raman scattering measurements. Our in-depth analysis of the phonon evolution with temperature and doping, gives interesting insights into the behaviour of these materials. All these systems undergo a metal-to-metal transition (TMMT), characterized by the development of intertwined spin and charge density waves, with the spin density wave preceding the charge density wave. These transitions manifest as pronounced anomalies in phonon self-energy parameters i.e. peak frequency and linewidth in the vicinity of the metal-to-metal transition. Several phonon modes show dramatic change (nearly an order of magnitude for some modes) in their softening rates across the TMMT, highlighting the sensitivity of the lattice dynamics to spin and charge order. These findings emphasize the crucial role of lattice DoF in mediating correlated ground states in layered nickelates.
Interplay of phonons, intertwined density waves, and induced spin density wave in trilayer nickelates Pr4-xLaxNi3O10
Categories
Abstract
Lattice degrees of freedom (DoF) play a central role in correlated electron systems, strongly influencing the dynamics of the underlying charge carriers and spin excitations. In nickelates, understanding the role of lattice is essential to unravel the interplay between charge, orbital, and spin degree of freedom in giving rise to various emergent phenomena reported recently. Here, we investigate the phononic DoF in a series of trilayer nickelates, namely Pr4-xLaxNi3O10 (where x = 0, 0.4, 1, 2, 3.6, and 4) using temperature and polarization dependent Raman scattering measurements. Our in-depth analysis of the phonon evolution with temperature and doping, gives interesting insights into the behaviour of these materials. All these systems undergo a metal-to-metal transition (TMMT), characterized by the development of intertwined spin and charge density waves, with the spin density wave preceding the charge density wave. These transitions manifest as pronounced anomalies in phonon self-energy parameters i.e. peak frequency and linewidth in the vicinity of the metal-to-metal transition. Several phonon modes show dramatic change (nearly an order of magnitude for some modes) in their softening rates across the TMMT, highlighting the sensitivity of the lattice dynamics to spin and charge order. These findings emphasize the crucial role of lattice DoF in mediating correlated ground states in layered nickelates.
Authors
Sonia Deswal, Dibyata Rout, Nirmalya Jana et al. (+3 more)
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