spinw.magstr method

Syntax

magout = magstr(obj,Name,Value)

Description

magout = magstr(obj,Name,Value) converts the internally stored magnetic structure (general Fourier representation) into a rotating frame representation with a single propagation vector, real magnetisation vectors and the normal axis of the rotation. The conversion is not always possible, in that case the best possible approximation is used, that might lead sometimes to unexpected magnetic structures. In this case a warning is triggered.

Example

The example shows the equivalent represenation of a simple spin helix in the $ab$-plane using Fourier components of the magnetization and using the rotating frame. The complex magnetization in the Fourier representation is converted into a real spin vector and a normal vector that defines the axis of rotation.

model = spinw
model.addatom('r',[0 0 0],'S',1)
model.genmagstr('mode','fourier','S',[1i 1 0]','k',[1/3 0 0])
model.mag_str.F

Output

   0.0000 - 1.0000i
   1.0000 + 0.0000i
   0.0000 + 0.0000i

model.magstr

Output

  struct with fields:
        S: [3×1 double]
        k: [0.3333 0 0]
        n: [0 0 1]
    N_ext: [1 1 1]
    exact: 1

model.magstr.S

Output

     0
     1
     0

Name-Value Pair Arguments

'exact'

If true, a warning appears in case the conversion is not exact. Default is true.

'nExt'

Size of the magnetic supercell, default value is the value stored in the spinw object (on which the Fourier expansion is defined).

'origin'

Origin in lattice units, the magnetic structure will be calculated relative to this point. Default value is [0 0 0]. Shifting the origin introduces an overall phase factor.

See Also

spinw.genmagstr