Hua Lv, Edouard Lesne, Rebeca Ibarra, Yan Sun, Anastasios Markou, and Claudia Felser
Phys. Rev. Materials 7, 054201 – Published 26 May 2023, Phys. Rev. Materials 7, 054201 (2023) – Realization of chiral multifold semimetal RhSi crystalline thin films (aps.org)
Nonmagnetic topological semimetals that combine chirality in real and momentum spaces host unconventional multifold fermions and exhibit exotic electronic and optical properties endowed by their topologically nontrivial electronic band structure. Although the synthesis of nonmagnetic chiral single crystals with a noncentrosymmetric cubic B20 structure is well established, their heteroepitaxial growth in crystalline thin films remains a notable challenge. In this study, we present the structural, magnetic, and electrical magnetotransport properties of 24- and 51-nm-thick films of a B20-RhSi stoichiometric compound grown by magnetron sputtering. RhSi crystalline thin films on Si (111) single-crystal substrates exhibit a preferred (111) orientation with twin domains. The RhSi films display a nonmagnetic ground state, and their electrical resistivity demonstrates a clear and nonsaturating metallic behavior from 300 to 5 K. Magnetotransport measurements reveal that hole-type carriers dominate the Hall response with multiband contributions to electronic transport in the system. The good agreement with the Bloch-Grüneisen model and our first-principles calculations confirms that temperature-dependent electrical resistivity is governed by electron-phonon scattering. The ability to grow textured-epitaxial thin films of nonmagnetic B20 chiral topological semimetals is an important step toward accessing and controlling their remarkable topological surface states for designing chiraltronic devices with novel optoelectronic or spintronic functionalities.