Putative Quantum Critical Point in Doped Skyrmion Binary Alloys

We report on Cr substitution triggered changes in the magnetic properties of a skyrmion binary alloy (Fe
1−x
Cr
x
)
0.6
Co
0.4
Si using x-ray diffraction and magnetization measurements. The x-ray diffraction patterns reveal an unaltered B20 cubic crystal stucture with increasing lattice constant. Magnetization analysis infers that the helical magnetic ordering of Fe
0.6
Co
0.4
Si is gradually suppressed to the absolute zero for the concentrations above x ≥ 0.4. Such a suppression is a clear indication of doping/substitution driven quantum phase transition with a quantum critical point to fall within 0.3 ≤ x ≤ 0.4.