Abstract
We show that light drives large-amplitude structural changes in thin films of the prototypical ferroelectric PbTiO 3 via direct coupling to its intrinsic photovoltaic response. Using time-resolved x-ray scattering to visualize atomic displacements on femtosecond time scales, photoinduced changes in the unit-cell tetragonality are observed. These are driven by the motion of photogenerated free charges within the ferroelectric and can be simply explained by a model including both shift and screening currents, associated with the displacement of electrons first antiparallel to and then parallel to the ferroelectric polarization direction.
Original language | English (US) |
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Article number | 087601 |
Journal | Physical review letters |
Volume | 108 |
Issue number | 8 |
DOIs | |
State | Published - Feb 23 2012 |
Externally published | Yes |