A new path for electron optics in solid-state systems

Schem­atic of the elec­tron–hole in­ter­fer­ence: Electron-​like (blue) and hole-​like (red) states co­ex­ist­ing in a double quantum well can in­ter­fere if the sys­tem is suit­ably biased. Im­age: ETH Zurich/D-​PHYS Zil­ber­berg group

Electrons can interfere in the same manner as water, acoustical or light waves do. When exploited in solid-state materials, such effects promise novel functionality for electronic devices, in which elements such as interferometers, lenses or collimators could be integrated for controlling electrons at the scale of mirco- and nanometres.

However, so far such effects have been demonstrated mainly in one-dimensional devices, for example in nanotubes, or under specific conditions in two-dimensional graphene devices.

Writing in Physical Review X, a collaboration including the Department of Physics groups of Klaus Ensslin, Thomas Ihn and Werner Wegscheider in the Laboratory for Solid State Physics and Oded Zilberberg at the Institute of Theoretical Physics, now introduces a novel general scenario for realizing electron optics in two dimensions.

The main functional principle of optical interferometers is the interference of monochromatic waves that propagate in the same direction.

In such interferometers, the interference can be observed as a periodic oscillation of the transmitted intensity on varying the wavelength of the light.

However, the period of the interference pattern strongly depends on the incident angle of the light, and, as a result, the interference pattern is averaged out if light is sent through the interferometer at all possible incident angles at once.

The same arguments apply to the interference of matter waves as described by quantum mechanics, and in particular to interferometers in which electrons interfere.

As part of their PhD projects, experimentalist Matija Karalic and theorist Antonio Štrkalj have investigated the phenomenon of electronic interference in a solid-state system consisting of two coupled semiconductor layers, InAs and GaSb.

They discovered that the band inversion and hybridization present in this system provide a novel transport mechanism that guarantees non-vanishing interference even when all angles of incidence occur.

Through a combination of transport measurements and theoretical modelling, they found that their devices operate as a Fabry-Pérot interferometer in which electrons and holes form hybrid states and interfere.

The significance of these results goes firmly beyond the specific InAs/GaSb realization explored in this work, as the reported mechanism requires solely the two ingredients of band inversion and hybridization. Therefore new paths are now open for engineering electron-optical phenomena in a broad variety of materials.

Media Contact

Andreas Trabesinger



All news from this category: Physics and Astronomy

This area deals with the fundamental laws and building blocks of nature and how they interact, the properties and the behavior of matter, and research into space and time and their structures.

innovations-report provides in-depth reports and articles on subjects such as astrophysics, laser technologies, nuclear, quantum, particle and solid-state physics, nanotechnologies, planetary research and findings (Mars, Venus) and developments related to the Hubble Telescope.

Back to the Homepage

Comments (0)

Write comment

Latest posts

Innovations through hair-thin optical fibres

Scientists at the University of Bonn have built hair-thin optical fibre filters in a very simple way. They are not only extremely compact and stable, but also colour-tunable. This means…

Artificial intelligence for sustainable agriculture

ZIM cooperation network on AI-based agricultural robotics launched The recently approved ZIM cooperation network “DeepFarmbots” met virtually for its official kick-off on November 25. The central goal of the network…

Teamwork in a molecule

Chemists at the University of Jena harness synergy effect of gallium Chemists at Friedrich Schiller University Jena have demonstrated the value of “teamwork” by successfully harnessing the interaction between two…

Partners & Sponsors

By continuing to use the site, you agree to the use of cookies. more information

The cookie settings on this website are set to "allow cookies" to give you the best browsing experience possible. If you continue to use this website without changing your cookie settings or you click "Accept" below then you are consenting to this.