Physical phenomena originating in the geometry of electronic wave functions can be observed in quantum materials. The Berry curvature is an emergent field characterizing the related geometric tensor.

An international team led by the University of Geneva (UNIGE) and consisting of researchers from Salerno, Utrecht and Delft has created a material in which electron dynamics can be controlled by bending the fabric of the space in which they evolve. Future optoelectronics, as well as next-generation electronic devices, are the application of this material.

The researchers created unique combinations of atoms in space that influence the material’s behavior using an advanced atomic-scale material fabrication system. Although technological applications are still a long way off, this material opens new avenues in investigating high-speed electromagnetic signal manipulation.

It can also be used to develop new sensors. The next step for the research team will be to observe how this material reacts to high electromagnetic frequencies to more accurately determine its possible applications.

Future telecommunications will require the development of new, incredibly powerful electronic devices capable of processing electromagnetic signals at previously unheard of speeds in the picosecond range.

This is unthinkable with today’s semiconductor materials, such as silicon, which is widely used in electronic components such as telephones, computers and game consoles.

To do this, scientists and industry are focusing on developing new quantum materials with unique properties that can be used to capture, alter and transmit information-carrying signals.

They can also operate in previously unexplored electromagnetic frequency ranges, opening up possibilities for high-speed communication systems.

Carmine Ortix, professor at the University of Salerno and coordinator of the theoretical study, said: “We designed an interface with an extremely thin layer of free electrons. It is sandwiched between strontium titanate and lanthanum aluminate, two insulating oxides. This combination allows us to obtain certain electronic geometric configurations that can be controlled on demand.

Andrea Caviglia, a professor in the Quantum Matter Physics Department of the UNIGE Faculty of Science and the study’s final author, said: “One of the most fascinating properties of quantum matter is that electrons can evolve in a curved space. The force fields, due to this distortion of the space inhabited by the electrons, generate dynamics that are totally absent in conventional materials. This is an excellent application of the principle of quantum superposition.”

Magazine reference:

  1. Lesne, Saǧlam, Battilomo, et al. Designing spin and orbital sources of Berry curvature at oxide interfaces. Natural Material.DOI: 10.1038/s41563-023-01498-0