Molecular simulator will aid the understanding of quantum magnetism

Magnetism is inherently governed by quantum mechanics, but the underlying theory is notoriously complex, especially for many-body systems. To unravel how magnetism emerges in materials, Wallenberg Academy Fellow Shantanu Mishra will develop an experimental quantum simulator.

A rigorous understanding of magnetism requires quantum mechanics, where magnetic behavior is described by mathematical objects called Hamiltonians. For materials that consist of several atoms, these Hamiltonians can often be too complex to solve theoretically, limiting our understanding of their magnetic properties.

Dr Shantanu Mishra, at IBM Research Europe in Zurich, Switzerland, will build a type of experimental quantum simulator. Using organic molecules, he will build nanostructures that mimic Hamiltonians central to quantum magnetism. Exploring magnetism with organic molecules—typically non-magnetic themselves—seems paradoxical. However, in certain molecular geometries electrons can be ‘forced’ to remain unpaired, leading to magnetism.

Shantanu Mishra will study magnetism in the nanostructures with scanning tunneling microscopy and atomic force microscopy. These techniques can characterize matter at the atomic scale. Using the microscopes, he can also build nanostructures with extreme precision—by controllably breaking or forming individual chemical bonds. The hope is that this project will provide new insights into some of physics’ most enigmatic phenomena, such as the behavior of quantum spin liquids and high-temperature superconductivity.

As a Wallenberg Academy Fellow, Shantanu Mishra will work at Chalmers University of Technology.

Photo: Patrik Lundin