Seminar: Unconventional superconductivity in materials with strong spin-orbit coupling

ABSTRACT

I will overview our recent work on layered superconductors where signatures of unconventional superconductivity are revealed or sometimes promoted by their response to magnetic fields. Magnetic correlations and superconductivity are usually antagonistic. However, in some situations external magnetic fields can be helpful in bringing to light new superconducting properties. An example is magnetic field induced transitions between superconducting states with different pairing symmetries as found in a heavy Fermion superconductor CeRh₂As₂, ion-intercalated MoS₂, and a layered centrosymmetric superconductor β-PdBi₂.  Our tunnelling spectroscopy on β-PdBi₂ under in-plane magnetic fields revealed a transition from conventional s-wave pairing to a nodal p-wave superconducting state. We show that the transition, marked by a discontinuous change in the tunneling spectra, originates from spin polarization and spin–momentum locking due to locally broken inversion symmetry. Remarkably, signatures of this transition also appear in magnetization, indicating the formation of a novel domain structure consisting of coexisting p-wave superconducting and normal regions. These findings offer a new experimental window into how spin textures, symmetry breaking, and strong spin–orbit coupling can stabilize unconventional superconductivity and generate emergent magnetic responses in layered materials.

BIOGRAPHY

Professor Irina Grigorieva is Professor of Physics in the Department of Physics and Astronomy at the University of Manchester, UK. She is a leading condensed matter physicist renowned for pioneering contributions to superconductivity—particularly at the nanoscale—as well as to magnetism and spintronics in graphene-based systems and the broader physical properties of two-dimensional heterostructures. Her recent research on alkali-ion intercalation in graphene-based heterostructures has also provided important insights into the fundamental processes underpinning rechargeable battery operation. Professor Grigorieva has been named a Highly Cited Researcher every year since 2017, received the IoP David Tabor Medal and Prize in 2019, and currently serves as Director of the EPSRC Centre for Doctoral Training in 2D Materials of Tomorrow.