Units of exchange coupling and DMI/anisotropic J
Posted: 02 Jul 2024, 03:12
Hi,
1) In VAMPIRE, exchange coupling strengths are given in units of Joules/link (which end up being on the order of 10^-22). In the TenPy documentation, the values used in the documentation are numbers on the order of 1 (e.g., for add_coupling()). Do the units matter? Can I just use values in meV? Apologies if I missed this in the documentation
2) If I specify anisotropic exchange \(J.S_i.S_j\) (Jxx,Jxy,Jxz,Jyx,Jyy,Jyz,Jzx,Jzy,Jzz) via add_coupling(), and my system has DMI too, will I need to specify DMI D separately (using \(D. S_i \times S_j\)) ? Or will the DMI be automatically treated from the anisotropic J values in TenPy, since they are related by: Dz = (Jxy - Jyx)/2, etc (since components of the DMI vector are related to the antisymmetric part of J)?
Thanks in advance!
1) In VAMPIRE, exchange coupling strengths are given in units of Joules/link (which end up being on the order of 10^-22). In the TenPy documentation, the values used in the documentation are numbers on the order of 1 (e.g., for add_coupling()). Do the units matter? Can I just use values in meV? Apologies if I missed this in the documentation
2) If I specify anisotropic exchange \(J.S_i.S_j\) (Jxx,Jxy,Jxz,Jyx,Jyy,Jyz,Jzx,Jzy,Jzz) via add_coupling(), and my system has DMI too, will I need to specify DMI D separately (using \(D. S_i \times S_j\)) ? Or will the DMI be automatically treated from the anisotropic J values in TenPy, since they are related by: Dz = (Jxy - Jyx)/2, etc (since components of the DMI vector are related to the antisymmetric part of J)?
Thanks in advance!