Grant running into millions for research into ultrathin materials

Since the discovery of two-dimensional (2D) materials about 10 years ago, research in this field has virtually exploded. A 2D material is a material consisting of a single layer or only a very few layers of atoms, and it is thus the absolutely thinnest material imaginable.

Professor Kristian Sommer Thygesen from DTU Physics has caused an international stir with his work in this field on several occasions. One example is his creation of a large database of calculated properties for thousands of different 2D materials— The Computational 2D Materials Database (C2DB)—which is used extensively by researchers worldwide. Another example is the physical models he has developed to describe the quantum mechanical processes that control the electronic and optical properties of the materials.

Functionalization of 2D materials

Now Kristian Sommer Thygesen has been awarded a Villum Investigator Grant to expand his work.

"I'm very pleased to receive the Villum Investigator Grant and—in the coming years—I will especially be focusing on how to functionalize 2D materials, thus bringing them one step closer to practical applications. There are several methods for tailoring the properties of the materials. With these, we can hopefully make them usable for new technologies such as low-cost catalysts for converting electrical energy into fuels, single photon light sources, or realization of qubits for quantum computers," he says.

The functionalization can consist of stacking different 2D materials on top of each other like LEGO bricks. In this way, you can create new materials with properties that can be completely different from the individual 2D layers.

Atomic defects can also be introduced in the 2D materials in a controlled manner. Such defects can function as active catalysis sites, or they can be used to capture individual electrons, making it possible to write and read individual quantum states. Another method that Kristian Sommer Thygesen has created himself is to shoot individual atoms in between the layers of stacked 2D materials. For example, this method can be used to make a non-magnetic material magnetic or an insulating material metallic.

"My work is purely theoretical. But—through collaboration with experimental groups locally and internationally—the new materials can be produced and tested in the laboratory," says Kristian Sommer Thygesen.

Artificial intelligence can accelerate discovery of new materials

As part of his coming work, Kristian Sommer Thygesen will use artificial intelligence in a new way. Where scientists have so far used the atomic structures of materials as input in artificial intelligence algorithms, he will establish whether other information can be used for better prediction of the properties of materials.

"What we've done so far is a bit like describing a person using data on height, weight, eye colour, shoe size, etc. We would like to take it a step further—to dig a little deeper into the DNA of the material so to speak—by supplementing the atomic structure with information about the electrons in the material. I'm curious as to how far we can go down this path by applying artificial intelligence to our data," says Kristian Sommer Thygesen.

The large-scale quantum mechanical calculations on which the work is based are performed by a supercomputer. DTU's own Niflheim computer is to be extended as the first part of the project.

"Even a supercomputer needs regular upgrading, just like our PCs. But this is money well spent, as Niflheim is optimized to be able to perform precisely the quantum mechanical calculations on which I and many of my DTU colleagues base our research," says Kristian Sommer Thygesen