Ultrafast relaxation dynamics of the antiferrodistortive phase in Ca doped SrTiO3

Abstract

The ultrafast dynamics of the octahedral rotation in Ca:SrTiO3 is studied by time resolved x-ray diffraction after photo excitation over the band gap. By monitoring the diffraction intensity of a superlattice reflection that is directly related to the structural order parameter of the soft-mode driven antiferrodistortive phase in Ca:SrTiO3, we observe a ultrafast relaxation on a 0.2 ps timescale of the rotation of the oxygen octahedron, which is found to be independent of the initial temperaure despite large changes in the corresponding soft-mode frequency. A further, much smaller reduction on a slower picosecond timescale is attributed to thermal effects. Time-dependent density-functional-theory calculations show that the fast response can be ascribed to an ultrafast displacive modification of the soft-mode potential towards the normal state, induced by holes created in the oxygen 2p states.

References in corpus (5)

• Non-thermal separation of electronic and structural orders in a persisting charge density wave
• Polaronic metal state at the LaAlO3/SrTiO3 interface
• Femtosecond dynamics of the collinear-to-spiral antiferromagnetic phase transition in CuO
• Probing photo-induced melting of antiferromagnetic order in La0.5Sr1.5MnO4 by ultrafast resonant soft X-ray diffraction
• Sub-diffraction sub-100 ps all-optical magnetic switching by passive wavefront shaping

Cited by in corpus (9)

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• Large photo-induced tuning of ferroelectricity in sliding ferroelectrics
• Topological polarons in halide perovskites
• Ultrafast transient increase of oxygen octahedral rotations in a perovskite
• Ultrafast Suppression of the Ferroelectric Instability in KTaO${}_3$
• Light-Driven Transitions in Quantum Paraelectrics
• Quantum nonlinear phononics route towards nonequilibrium materials engineering: Melting dynamics of a ferrielectric charge density wave
• Kapitza stabilization of quantum critical order