ECAR Seminar: Dr. Onur Erten

Title: Moire magnets: skyrmions & quantum spin liquids

Speaker: Dr Onur Erten
Date: Today, 11:00 am
Place: TAM Building Conference Hall


Two-dimensional van der Waals materials can be arranged in different stacking patterns or can be twisted to form moire superlattices. These can drastically alter their properties and lead to new emergent phenomena. In this talk, I will focus on moire superlattices of van der Waals magnets and discuss how new phases can be created by utilizing twisting. In the  first part, I will consider chiral magnets and show that stacking dependent interlayer exchange can be used to create skyrmions (1). I will further illustrate this mechanism by applying it to bilayers of Cr-based trihalides (2). In the second part of my talk, I will focus on SU(2) invariant Kitaev spin-orbital bilayers. I will discuss how interlayer exchange can lead to a gapped quantum spin liquid and the stability of this phase under small twist angles (3, 4, 5). Time permitting, I will conclude with constructing similar models in quasicrystals and discuss the emergence of various chiral quantum spin liquids in this case (6).

(1) M. Akram, O. Erten Phys. Rev. B 103, L140406 (2021).

(2) M. Akram, H. LaBollita, D. Dey, J. Kapeghian, O. Erten, and A. Botana

Nano Lett. 15, 6633 (2021).

(3) E. Nica, M. Akram. A. Vijayvargia, R. Moessner, O. Erten npj Quantum

Mat. 8, 9 (2023).

(4) A. A. Vijayvargia, E. Nica, R. Moessner, Y.-M. Lu, O. Erten Phys. Rev.

Research 5, L022062 (2023).

(5) M. Akram, E. Nica, Y.-M. Lu, O. Erten arxiv:2304.09891 (2023).

(6) M. A. Keskiner, O. Erten, M. O. Oktel, (in preparation).