An international team of scientists led by Le Phuong Hoang and Giuseppe Mercurio from European XFEL has unveiled a new way to manipulate the properties of ferroelectric materials using light, achieving control on ultrafast timescales. The breakthrough points to a future where memory devices and electronic components could become dramatically faster and more energy-efficient.
Ferroelectrics are crystals in which positive and negative charges are slightly displaced, producing an internal electric field known as spontaneous polarization. This polarization can normally be reversed only with an applied electric field, a feature that has made ferroelectrics highly attractive for applications such as nanoscale switches and advanced data storage.
Using the exceptionally bright and short X-ray flashes and optical lasers, the team studied barium titanate (BaTiO₃), a prototypical ferroelectric oxide. They tracked simultaneous changes in polarization, lattice structure, and electronic state with an unprecedented temporal resolution of 90 femtoseconds - about one-millionth of a billionth of a second.
The experiments revealed a striking effect: within only 350 femtoseconds of laser excitation, the polarization of the material shifted dramatically, while the underlying crystal lattice remained essentially unchanged. For the first time, researchers were able to show that polarization can be altered independently of lattice distortion, something that had long been theorized but never observed.
"This result tells us that electrons excited by light can drive changes in polarization far more quickly than the crystal structure itself can respond," explained Le Phuong Hoang. "It gives us a new lever for controlling material behavior at the electronic level."
The implications are far-reaching. "If light alone can achieve what previously required complex circuitry and external fields, the design of future devices could become much simpler," added Giuseppe Mercurio, scientist at European XFEL. "We may even find ways to apply similar principles to materials that combine electric and magnetic properties, opening new frontiers for multifunctional electronics."
Next-generation free-electron lasers open windows onto length and time scales once beyond reach, transforming what we can observe and understand, says Zhong Yin, Associate Professor at Tohoku University's SRIS.
The study demonstrates not only a new mechanism for controlling material properties but also one that is faster and more versatile than conventional approaches. By leveraging ultrafast light pulses rather than electric circuitry, researchers believe the work marks an important step toward light-controlled electronics with potential applications in sensing technologies, data processing, and energy-efficient information storage.
- Publication Details:
Title: Ultrafast decoupling of polarization and strain in ferroelectric BaTiO3
Authors: Le Phuong Hoang, David Pesquera, Gerard N. Hinsley, Robert Carley, Laurent Mercadier, Martin Teichmann, Elena Martina Unterleutner, Daniel Knez, Martina Dienstleder, Saptam Ganguly, Teguh Citra Asmara, Giacomo Merzoni, Sergii Parchenko, Justine Schlappa, Zhong Yin, José Manuel Caicedo Roque, José Santiso, Irena Spasojevic, Cammille Carinan, Tien-Lin Lee, Kai Rossnagel, Jörg Zegenhagen, Gustau Catalan, Ivan A. Vartanyants, Giuseppe Mercurio
Journal: Nature Communications
