QUEST - QUantum matErials for Sustainable Technologies

Topological or not? An ARPES answer on the candidate high-TC FM TI Mn1+xSb2−xTe4

Dec 2, 2024, 9:00 AM

30m

Sala Kastler (Adriatico Guesthouse, ICTP, Trieste, Italy)

Invited Oral Session 1

Speaker

Prof. Mark Golden (University of Amsterdam, Institute of Physics, van der Waals-Zeeman Intitute, Quantum Materials.)

Description

The combination of nontrivial band topology & magnetism results in a wide variety of exotic electronic phases that -if realised at high temperatures- could revolutionise fields like spintronics or low-power consumption electronics. The new, second-generation ferrimagnetic compound Mn${}_{1+x}$Sb${}_{2-x}$Te${}_4$ (0.1 ≤ x ≤ 1, abbreviated here as MST) promises to host the quantum anomalous Hall effect (QAHE) and other topological phases at higher temperatures than any of its predecessors, wth TCurie’s up to 73K. Their long-range magnetic order is confirmed and thus the big question is “are they topologically non-trivial?”. MST crystals are significantly p-type doped, meaning the Dirac point of the putative TSS’s is well above EF. Nevertheless, I will aim to persuade you that our temperature-dependent ARPES data (recorded at MAX-IV and CLS) clearly argue that the answer is “yes”.

Research carried out in collaboration with:
Sergio Barquero Pierantoni (UvA), Anna Isaeva (UvA and TU Dortmund), Katya Kochetkova (IFW Dresden & UvA), Saumya Mukherjee (UvA, now SPECS), M. Farhan Tanzim (UvA), Irene Aguilera (UvA), Marie Tardieux (UvA), Falk Pabst (UvA), Floris Kooij (UU), J. Oziecki (MAX-IV), Craig Polley (MAX-IV), Sergey Gorovokov (CLS) and Marta Zonno (CLS, now SOLEIL) and Steef Smit (UBC)

Funded by an IoP grant, associated to the QuMat Consortium (qumat.org)