2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/156175In isotropic macroscopic quantum systems vortex lines can be formed while in anisotropic systems also vortex sheets are possible. Based on measurements of superfluid 3He-A, we present the principles which select between these two competing forms of quantized vorticity: sheets displace lines if the frequency of the external field exceeds a critical limit. The resulting topologically stable state consists of multiple vortex sheets and has much faster dynamics than the state with vortex lines.RevTex, 5 pages, sumbitted to Phys. Rev. LettCondensed Mattertext