Unveiling the Role of Spin Currents on the Giant Rashba Splitting in Single-Layer WSe2

• Published in: The journal of physical chemistry letters Vol. 15; no. 29; pp. 7442 - 7448
• Main Authors: Boccuni, Alberto, Peluzo, Bárbara Maria Teixeira Costa, Bodo, Filippo, Ambrogio, Giacomo, Maul, Jefferson, Mitoli, Davide, Vignale, Giovanni, Pittalis, Stefano, Kraka, Elfi, Desmarais, Jacques K., Erba, Alessandro
• Format: Journal Article
• Language: English
• Published: American Chemical Society 25-07-2024
• Subjects: Physical Insights into Materials and Molecular Properties
• ISSN: 1948-7185; 1948-7185
• DOI: 10.1021/acs.jpclett.4c01607

The Rashba spin splitting in uniaxial, inversion-asymmetric materials has attracted considerable interest for spintronic applications. The most widely used theoretical framework to model such states is Kohn–Sham density functional theory (DFT) in combination with standard (semi)­local exchange–correlation density functional approximations (DFAs). However, in the presence of spin–orbit coupling, DFT misses contributions due to modification of the many-body interaction by spin currents J⃗. Inclusion of the latter effects requires a spin current DFT (SCDFT) formulation, which is seldom considered. We investigate the giant Rashba splitting in single-layer WSe2, and we quantify the effect of including spin currents in DFAs of the SCDFT. Crucially, we show that SCDFT allows fully capturing the giant Rashba band splitting in single-layer WSe2, otherwise previously systematically underestimated by standard (semi)­local DFAs within the DFT framework. We find the inclusion of J⃗ on the DFA increases the Rashba splitting by about 20%.