VP14-10 Exchange effects from a magnetic substrate in transition metal dichalcogenides zigzag ribbons
Creators: Mónica Salazar
Oscar Avalos
Juan Pablo Ramos
Publisher: name: IEEE
Year: 2025

Majorana zero modes (MZMs) have been predicted in semiconductor materials in the presence of an external magnetic field and proximitized to a superconductor. Nevertheless, controlling laboratory conditions to observe MZMs and their interesting non-Abelian properties remains challenging [1]. In this scenario, 2D transition metal dichalcogenides (TMDs) proximitized with ferromagnetic insulators emerge as an interesting alternative due to their properties, such as strong and intrinsic spin-orbit coupling [2]. We propose a comparative study of the effects of exchange and Rashba interactions on tungsten diselenide (WSe2) and tungsten ditelluride (WTe2) placed on top of europium oxide (EuO). As a first step, we explore the emergence of spin-polarized edge states in a zigzag TMD ribbon proximitized with a ferromagnetic substrate. In both cases, we demonstrate the capability of breaking time-reversal symmetry in the dichalcogenides through different magnitudes of Rashba and exchange fields. Additionally, the case of the WSe2/EuO zigzag ribbon shows isolated edge states in the material's band gap, indicating that these states are likely more accessible experimentally. With our study, we pave the way for proposing new observations of MZMs in TMDs.References: [1] Lutchyn, R. M., Bakkers, E. P., Kouwenhoven, L. P., Krogstrup, P., Marcus, C. M., & Oreg, Y. (2018). Majorana zero modes in superconductor–semiconductor heterostructures. Nature Reviews Materials, 3(5), 52-68. [2] Cortés, N., Ávalos-Ovando, O., Rosales, L., Orellana, P. A., & Ulloa, S. E. (2019). Tunable spin-polarized edge currents in proximitized transition metal dichalcogenides. Physical Review Letters, 122(8), 086401.
Majorana zero modes (MZMs) have been predicted in semiconductor materials in the presence of an external magnetic field and proximitized to a superconductor. Nevertheless, controlling laboratory conditions to observe MZMs and their interesting non-Abelian properties remains challenging [1]. In this scenario, 2D transition metal dichalcogenides (TMDs) proximitized with ferromagnetic insulators emerge as an interesting alternative due to their properties, such as strong and intrinsic spin-orbit coupling [2]. We propose a comparative study of the effects of exchange and Rashba interactions on tungsten diselenide (WSe2) and tungsten ditelluride (WTe2) placed on top of europium oxide (EuO). As a first step, we explore the emergence of spin-polarized edge states in a zigzag TMD ribbon proximitized with a ferromagnetic substrate. In both cases, we demonstrate the capability of breaking time-reversal symmetry in the dichalcogenides through different magnitudes of Rashba and exchange fields. Additionally, the case of the WSe2/EuO zigzag ribbon shows isolated edge states in the material's band gap, indicating that these states are likely more accessible experimentally. With our study, we pave the way for proposing new observations of MZMs in TMDs.References: [1] Lutchyn, R. M., Bakkers, E. P., Kouwenhoven, L. P., Krogstrup, P., Marcus, C. M., & Oreg, Y. (2018). Majorana zero modes in superconductor–semiconductor heterostructures. Nature Reviews Materials, 3(5), 52-68. [2] Cortés, N., Ávalos-Ovando, O., Rosales, L., Orellana, P. A., & Ulloa, S. E. (2019). Tunable spin-polarized edge currents in proximitized transition metal dichalcogenides. Physical Review Letters, 122(8), 086401.