Swirls of Light to Enable Researchers to Observe Previously Invisible Quantum States
Light Swirls Provide Insights Into the Quantum World
A new method uses swirls of light to enable researchers to observe previously invisible quantum states of electrons. The method was developed by physicists from Martin Luther University Halle-Wittenberg (MLU) and an international team of researchers. It promises to deliver new insights into electron motion, which is crucial in understanding material properties such as electrical conductivity, magnetism and molecular structures. The free electron laser FERMI in Italy was used to provide experimental proof and the results were published in the journal Nature Photonics.
Optical microscopes gave the world its first glimpse of the microcosm of bacteria and cells. However, the wavelength of light limits the resolution of these microscopes. “The quantum world remains invisible,” says Dr. Jonas Wätzel from the Institute of Physics at MLU, who is a member of the research group led by Professor Jamal Berakdar. “In atoms, the spatial expansion of quantum particles, like electrons, is many times smaller than the wavelength of light, making imaging using traditional optical microscopy impossible.”
However, light can carry a considerable amount of energy. “When the energy of a photon is strong enough to knock an electron out of the material, it is called the photoelectric effect,” Wätzel explains. This effect was predicted by Einstein. Spectrometers can detect the properties of the emitted photoelectron. Photoelectron spectroscopy is currently the primary tool used to analyze a material’s electronic structure. “Many quantum states aren’t excited by photons and thus remain invisible,” Wätzel explains.