Theoretical Study of Co-Existent Exotic Magnetism and Unconventional Superconductivity

Lars Nordström
Lars Nordström. Photo: Mikael Wallerstedt.

Project Description

Project title: Theoretical Study of Co-Existent Exotic Magnetism and Unconventional Superconductivity
Main applicant: Lars Nordström, Division of Materials Theory
Grant amount: SEK 3 550 000 for the period 2023-2026

I will study materials with exotic magnetic ordering and unconventional superconductivity based on state-of-the-art realistic electronic structure calculations. This type of materials often belong to heavy fermion systems and exhibit peculiar ground states.

Within this project I will adopt an unified picture of magnetism where not only spin moments but also higher ranked multipoles play vital roles and states without conventional spin dipole ordering are also included within the concept of exotic magnetic ordering. Due to the obstacles to observe them by experiments they are often going under the concept of hidden order. Importantly and fascinatingly, a large number of these exotic magnets display unconventional superconductivity at low temperature.

To understand these states, magnetic and superconducting, I will perform realistic electronic structure calculations that incorporate correlations effects. The magnetic and superconducting states will be treated on the same footing by symmetry breaking with appropriate mean-field approximations of the general local correlation within the open f-shell.

Questions that will dealt with are:

What are the possible order parameters in exotic magnetic and superconducting heavy fermion materials? What are the topological characters of the low energy quasi-particles in the ordered states?

During this project I mainly aim to understand the different unconventional superconductivities in magnetic heavy fermion materials, such as URhGe and UTe2.

Last modified: 2023-03-22