CONDENSED MATTER
Magnetic topological alloys based on the Cd$_3$As$_2$ dirac semimetal: doping with Cr, Mn, and Fe
E. T. Kulatova,
Yu. A. Uspenskiib,
K. I. Kugelcd a Prokhorov General Physics Institute, Russian Academy of Sciences, Moscow, 119991 Russia
b Lebedev Physical Institute, Russian Academy of Sciences, Moscow, 119991 Russia
c HSE University, Moscow, 101000 Russia
d Institute for Theoretical and Applied Electrodynamics, Russian Academy of Sciences, Moscow, 125412 Russia
Abstract:
According to theoretical models, the doping of a Dirac semimetal with magnetic atoms splits the Dirac cone into two Weyl cones, thus forming a magnetic Weyl semimetal attractive for applications. In this work, such phenomenon is investigated ab initio on an example of the Cd
$_3$As
$_2$ Dirac semimetal doped with Cr, Mn, and Fe. For the cases of ferromagnetic and antiferromagnetic ordering in (Cd
$_{1-x}$M
$_x$)
$_3$As
$_2$ alloys (M = Cr, Mn, Fe), the band structure, Fermi surface, electron velocity at the Fermi level, and the Drude plasma frequency are calculated, and the relaxation time in the limit
$T\to 0$ K is estimated. The calculations demonstrate that one Weyl cone in ferromagnetic alloys is usually destroyed due to the hybridization of electronic states of Cd
$_3$As
$_2$ with M
$3d$ orbitals. The condition for the conservation of the second Weyl cone is its falling into an energy window free of M
$3d$ states. The existence of such windows is closely related to the energy and filling of
$3d \uparrow $ and
$3d\downarrow$ bands of M atoms, the type of spin ordering (ferro- or antiferromagnetic), and the chemical composition of the alloy. In particular, such windows are absent in antiferromagnetic alloys, except the case of M = Mn. The estimates show that the Weyl cone, if preserved, dominates in the transport properties of (Cd
$_{1-x}$M
$_x$)
$_3$As
$_2$, which agrees with the available experimental results.
Received: 17.03.2025
Revised: 04.04.2025
Accepted: 06.04.2025
DOI:
10.31857/S0370274X25050104
Fulltext:
PDF file (2515 kB)
First page:
PDF file