Revolutionary Research at Cornell Engineering

Cornell Engineering researchers have made a groundbreaking discovery: ultra-fast infrared light pulses can trigger rapid, atomic 'breathing' in synthetic thin films. This remarkable strain-driven process allows materials to expand and contract billions of times per second, offering the potential to instantly switch electronic, magnetic, or optical properties.

The Power of Light Revealed

Published in *Physical Review Letters*, this research reinforces the idea that manipulating materials through strain is effective, but using light is a less explored avenue. Nicole Benedek, a co-leader of the study, highlighted the complexities of understanding light interactions and the challenges in modeling these effects in detail.

Dynamic Strain: A New Frontier

Benedek’s computational theories helped predict how optimal light frequencies could be combined with the right materials to create a dynamic strain that can change and revert. Unlike traditional methods where strain is permanently embedded in the material, this technique allows for temporary alterations.

Harnessing Terahertz Light

The team discovered that firing picosecond bursts of terahertz light—at frequencies resembling lattice vibrations—could induce the desired atomic deformations. As Andrej Singer explains, this allows atoms to oscillate like children on swings, amplifying their movements and resulting in significant lattice expansion.

Choosing the Right Material: The Unassuming Lanthanum Aluminate

Interestingly, the researchers chose lanthanum aluminate for their experiments, a seemingly unremarkable material. Benedek noted that opting for something simpler would streamline their research process. Yet, lanthanum aluminate turned out to be anything but ordinary.

Collaboration with Experts

With the help of Darrell Schlom, a prominent figure in materials science at Cornell, the thin films of lanthanum aluminate were synthesized. The experiments were conducted alongside collaborators from Stanford's SLAC National Accelerator Laboratory using advanced free-electron lasers.

Unexpected Structural Enhancements

Upon analysis, the team confirmed that the terahertz light bursts not only induced the predicted strains but also permanently enhanced the structural ordering of lanthanum aluminate. This finding indicated that excited phonons could transform domain boundaries into a more crystalline, ordered state.

New Possibilities with Low-Frequency Light

The revelation that low-frequency light could manipulate materials opens the door to numerous new applications. Researchers envision the possibility of toggling between different states, activating or deactivating electronic and magnetic properties, and even facilitating structural changes essential for superconductivity.

A Fusion of Methods for Future Discoveries

Singer encapsulates the significance of this study: "By integrating theory, synthesis, and characterization, we are uncovering how light interacts with complex-oxide materials, paving the way for accessing properties that standard methods cannot achieve."