Physics of Majoranas

Welcome to our group webpage!

We are pursuing research at the International Centre for Interfacing Magnetism and Superconductivity with Topological Matter – MagTop and Department of Applied Physics, Aalto University. Our research focuses on the theory of exciton condensates, superconductors, magnetism, topological materials and topological quantum computation.

Topology in condensed matter systems?

Topology is a branch of mathematics concerned with properties of objects, which are preserved under continuous deformations, including stretching and bending. In past few years a new field of topological materials has emerged in condensed matter physics, based on the wide range of consequences that result from the realization that certain properties of physical systems can be expressed as topological invariants, which are insensitive to local perturbations. The language of topology allows to connect seemingly separate physical phenomena occurring in high-energy and condensed matter physics to each other. Topological quantum numbers are the foundation for the most accurate quantization of observables in condensed matter systems e.g. the ratio of the frequency and dc voltage in the ac Josephson effect and the quantization of the conductance in the quantum Hall effect. The same robustness and accuracy may soon be utilized to revolutionize the field of quantum computing with the help of topological qubits based on Majorana zero modes. Moreover, the consideration of the momentum space topology is currently guiding the search of new exotic phases of matter.

Want to know more about these topics? Recommendations for popular science articles:

Press Release: The Nobel Prize in Physics 2016 for theoretical discoveries of topological phase transitions and topological phases of matter. "They have used advanced mathematical methods to study unusual phases, or states, of matter, such as superconductors, superfluids or thin magnetic films. Thanks to their pioneering work, the hunt is now on for new and exotic phases of matter. Many people are hopeful of future applications in both materials science and electronics."

F. Wilczek, Majorana returns, Nature Physics 5, 614 (2009). "In his short career, Ettore Majorana made several profound contributions. One of them, his concept of 'Majorana fermions' — particles that are their own antiparticle — is finding ever wider relevance in modern physics."

T. Hyart, Viewpoint: A Magnetic-Field-Free Exciton Condensate, Physics 11, 39 (2018).

T. Heikkilä and T. Hyart, Moiré with flat bands is different, Europhys. News 50, 24 (2019).

We are also organizing a seminar series on Topological Materials.