Linear dispersion of Dirac fermions in (Cd 1–x–y Zn x Mn y ) 3 As 2 , х+y = 0.2, у = 0.02, 0.04, 0.06, 0.08 solid solutions

• Published in: Physica scripta Vol. 96; no. 12; p. 125856
• Main Authors: Zakhvalinskii, Vasilii S, Nikulicheva, Tatyana B, Pilyuk, Evgeny A, Nguyen, Hong T.T, Lähderanta, Erkki, Shakhov, Mikhail A, Isaeva, Natalia O, Kochura, Alexey V
• Format: Journal Article
• Language: English
• Published: 01.12.2021
• ISSN: 0031-8949; 1402-4896
• DOI: 10.1088/1402-4896/ac3873

Abstract Based on the results of the Shubnikov-de Haas oscillations study in single-crystalline diluted magnetic semiconductors (Cd 1−x−y Zn x Mn y ) 3 As 2 (CZMA) with х  +  y  = 0.2 and Mn content ( у  = 0.02, 0.04, 0.06, 0.08) at temperatures T  = 4.2 to 30 K and magnetic fields B  = 0 to 12 T under hydrostatic pressure p  = 0 and 10 kbar, the values of the phase shift β , indicating the existence of the Berry phase in all samples were determined. Thickness of two-dimensional surface topological nanolayers in CZMA ( х  +  y  = 0.2) single crystals was defined. The rise in Mn concentration led to an increase in the concentration of charge carriers in the 2D surface layers n 2 D and a decrease in its mobility μ 2D . The reduced cyclotron mass m с (0)/ m 0 , depending on the Fermi wave vector k F , experimentally observed from the Shubnikov-de Haas oscillations, which was in a good agreement with the prediction theory of linear dependence and experimental results in topological insulator single crystals Bi 2 Se 3 indicated that Dirac fermions were present in a diluted magnetic semiconductor CZMA system with х  +  y  = 0.2. The damping of the Shubnikov-de Haas oscillations for pressures p  = 0 and 10 kbar in the CZMA sample ( х  +  y  = 0.2; y  = 0.2) was found to be associated with an amplitude decrease by spin splitting (Zeeman effect). From the analysis of experimental data, the effective Lande factor g  = 7.63 and 7.87 and the band gap Δ =35.3 and 9.7 meV at p = 0 and 10 kbar, respectively, were obtained.