New plasmonic wave analysis reveals spin texture of meron pairs in quantum world

Scientists have come up with an interesting technique to study plasmonic waves, combining time-resolved electron microscopy with the use of multi-polarization lasers.

Representational image depicting spin textures.

For a long time, scientists have been trying to devise ways to study a special type of light wave called plasmonic waves. These are ripples of electron oscillations that travel along the surface of metals, like waves on water, when light interacts with the metal.

Plasmonic waves can concentrate light into tiny spaces, creating a bridge between light and the nanoscale world. They have numerous applications. For instance, using these waves scientists can examine tiny biomolecules, detect microscopic changes in biological and chemical reactions, develop high-resolution medical imaging tools, enhance solar cell efficiency, and boost the performance of photonic devices.


Now, a new study has revealed an interesting technique to examine plasmonic waves. The study authors claim their technique is probably the most precise plasmonic wave analysis method developed so far.

Combining microscopy with lasers

As part of the study, researchers focused on plasmon polaritons, special waves that occur when light interacts with electrons on the surface of a metal. These are considered hybrid waves as they are a mix of light (photons) and electron vibrations (plasmons), traveling together along the surface of the metal.

Scientists have been using time-resolved electron microscopy to study plasmon polaritons. This approach involves using ultra-short pulses of electrons to freeze and observe the motion of atoms and molecules.

The study authors integrated this approach with multi-polarization lasers, a technique deployed to study material properties using multiple linearly polarized lasers that are placed on top of one another. This two-in-one method can reveal plasmonic wave behavior with high accuracy and great depth, according to the researchers.

Testing the approach to study meron pairs

Various magnetic and quantum systems contain tiny swirling patterns called meron pairs. These patterns or spin textures can be reconstructed using electric field and magnetic field vectors of surface plasmon polaritons.

The study authors employed numerous time-delayed laser pulses with multiple polarizations to determine the magnetic vectors. Using their approach they successfully reconstructed the spin texture and topological features of a system.

Moreover, it also revealed insights into the stability of the spin texture during the experiment. Such insights can shed light on the factors that keep a material intact at the nanoscale.
The next goal is to use this approach to study other complex plasmon polaritons. Hopefully, the method will improve our understanding of nanoscale phenomena.