sw_magdomain

calculates the spin-spin correlation function for magnetic domains

Syntax

spectra = sw_magdomain(spectra,Name,Value)

Description

spectra = sw_magdomain(spectra,Name,Value) calculates spin-spin correlation function averaged over magnetic domains that are related by a point group operation. Several domains with different volume ratios can be defined. The spin-spin correlation function will be rotated and summed according to the domains. The rotations of the magnetic domains are defined in the $xyz$ coordinate system, same as the coordinate system for the spin-spin correlation function. The function only rotates the $\mathcal{S}^{\alpha\beta}$ components of the spin, but not the momentum $Q$ , thus it cannot be used to simulate magnetic domains with different propagation vector.

Examples

The above example calculates the spectrum for magnetic domains that are related by a 90 ° rotation around the $z$ -axis (perpendicular to the $ab$ plane). All domains have equal volume.

spec = cryst.spinwave({[0 0 0] [1 0 0]})
spec = sw_magdomain(spec,'axis',[0 0 1],'angled',[0 90 180 270]);

Input Arguments

spectra: Calculated spin wave spectrum.

Name-Value Pair Arguments

'axis': Defines axis of rotation to generate domains in the $xyz$ coordinate system, row vector with 3 elements.
'angle': Defines the angle of rotation to generate domains in radian units, multiple domains can be defined if angle is a row vector with $n_{dom}$ number of elements.
'angled': Same as the angle parameter, just in ° units.
'rotC': Rotation matrices, that define crystallographic domains, alternative input instead of angle and axis, matrix with dimensions of $[3\times 3\times n_{dom}]$ .
'vol': Volume fractions of the domains in a row vector with $n_{dom}$ number of elements. Default value is ones(1,nDom).

Output Arguments

spectra

Spectrum (Struct) with the following additional fields:

Sab The multi domain spectrum will be stored here.
Sabraw The original single domain spectrum is kept here, so that a consecutive run of sw_magdomain will use the original single domain spectrum, without the need of recalculating the full spectrum.
domVol Volume of each domains in a row vector with $n_{dom}$ number of elements.
domRotC Rotation matrices for each domain, with dimensions of $[3\times 3\times n_{dom}]$ .