First principles study of structural, magnetic and electronic properties of CrAs

Abstract

We report ab initio density functional calculations of the structural and magnetic properties, and the electronic structure of CrAs. To simulate the observed pressure-driven experimental results, we perform our analysis for different volumes of the unit cell, showing that the structural, magnetic and electronic properties strongly depend on the size of the cell. We find that the calculated quantities are in good agreement with the experimental data, and we review our results in terms of the observed superconductivity.

A minimal tight-binding model for the quasi-one-dimensional superconductor K2Cr3As3

“…The total DOS reported in figure 2(b) exhibits, as expected, peaks in correspondence of the flat portions of the energy spectrum. Similarly to what found for CrAs [22,34,35], the DOS has a predominant As character at energies of the order of ±2 eV away from the Fermi level. The peaks near −0.5 and 1 eV are instead associated with the Cr-d yz and d xz orbitals, whereas, differently from what happens for CrAs, there is no clear prevalence of Cr states around the Fermi energy, but rather the Cr-d xy , d x y 2 2 and d z 2 and the As-p x and p y contributions are all relevant, as we will point out below in more detail.…”

“…The magnetism in these systems has been studied within the generalized gradient approximation (GGA) [15,30]. We use the LDA approach that gives lower magnetic moment and weaker magnetic properties in metals with respect to the GGA [22,31]. The magnetic properties of these compounds are still under debate [12] and it is not clear which is the best exchange-correlation functional that should be used.…”

Mechanism for transitions between ferromagnetic and antiferromagnetic orders in d-electron metallic magnets

“…The proximity to AFM/FM transition, present in Fig. 3b already for U /| ε d | ≃ 0.6, can justify why ab-initio calculations, that are known to slightly overestimate tendency toward FM, support stable FM in CrAs under pressure 25 .…”

“…Second promising candidate material to realize two-channel Stoner physics is itinerant d -electron antiferromagnet CrAs. Band structure calculations for this material suggest: ( i ) predominant role of mixed p - d states near the Fermi level 25–27 ; ( ii ) proximity between FM and AFM states 25 ; ( iii ) weak degree of correlations due to a very wide p -band (large | t c |) 25–27 ; ( iv ) consistency with (Cr 0 )(As 0 ) oxidation state, implying occupation of 3 d -orbital larger but close to half-filling 26 .…”

Topological Transition in Pb1-xSnxSe using Meta-GGA Exchange-Correlation Functional

“…Unlike the surfaces states in the conventional Z 2 topological insulators [17], the surface states of TCI are protected by crystalline symmetry, instead of time reversal symmetry. We would like to point out that also the topological crystalline metallic phases have been proposed to be present in orthorhombic structures [18][19][20][21][22].…”