Stability of Skyrmion Crystal Phase in Centrosymmetric Distorted Triangular-Lattice Antiferromagnets

The stability of a magnetic skyrmion crystal in a centrosymmetric orthorhombic lattice system is numerically investigated. By performing the simulated annealing for an effective spin model with the momentum-resolved interaction on a uniaxially distorted triangular lattice, we find that the skyrmion crystal is robustly realized when dominant interaction channels consist of the double-$Q$ structure in momentum space. Moreover, we show that an anti-type skyrmion crystal with the opposite skyrmion number is obtained by tuning the sign of the bond-dependent anisotropic exchange interaction that originates from the relativistic spin-orbit coupling.