Dear ALPS team,
I am trying to obtain magnetization curve of anisotropic XY model on frustrated diamond spin chain in transverse magnetic field (m^x) using full diagonalization. For this purpose I have prepared such input file for delta=1.5;
LATTICE="lattice_diamond" MODEL="spin" LATTICE_LIBRARY="lattice-diamond.xml" local_S=1/2
Jxy1 = 0.85 Jxy2 = 3.0 Jxy3 = 1.15
Jz1 = 1.275 Jz2 = 4.5 Jz3 = 1.725
L = 2 T = 0.001
{Gamma =4;} {Gamma =4.05;} {Gamma =4.1;} {Gamma =4.15;} {Gamma =4.2;} {Gamma =4.25;} {Gamma =4.3;} {Gamma =4.35;} {Gamma =4.4;} {Gamma =4.45;} {Gamma =4.5;} {Gamma =4.55;} {Gamma =4.6;} {Gamma =4.65;} {Gamma =4.7;} {Gamma =4.75;} {Gamma =4.8;} {Gamma =4.85;} {Gamma =4.9;} {Gamma =4.95;} {Gamma =5;} {Gamma =5.05;} {Gamma =5.1;} {Gamma =5.15;} {Gamma =5.2;} {Gamma =5.25;} {Gamma =5.3;} {Gamma =5.35;} {Gamma =5.4;} {Gamma =5.45;} {Gamma =5.5;} {Gamma =5.55;} {Gamma =5.6;} {Gamma =5.65;} {Gamma =5.7;} {Gamma =5.75;} {Gamma =5.8;} {Gamma =5.85;} {Gamma =5.9;} {Gamma =5.95;} {Gamma =6;}
lattice-diamond.xml is:
<LATTICES> <LATTICEGRAPH name="lattice_diamond"> <FINITELATTICE> <LATTICE dimension="1"> <BASIS> <VECTOR>1</VECTOR> </BASIS> </LATTICE> <PARAMETER name="L"/> <EXTENT size="L"/> <BOUNDARY type="periodic"/> </FINITELATTICE> <UNITCELL dimension="1" vertices="3"> <VERTEX id="1" type="0"> </VERTEX> <VERTEX id="2" type="0"> </VERTEX> <VERTEX id="3" type="0"> </VERTEX> <EDGE type="2"> <SOURCE vertex="1"/> <TARGET vertex="2"/> </EDGE> <EDGE type="3"> <SOURCE vertex="1"/> <TARGET vertex="3"/> </EDGE> <EDGE type="1"> <SOURCE vertex="2"/> <TARGET vertex="3"/> </EDGE> <EDGE type="3"> <SOURCE vertex="3"/> <TARGET vertex="2" offset="1"/> </EDGE> <EDGE type="1"> <SOURCE vertex="3"/> <TARGET vertex="1" offset="1"/> </EDGE> </UNITCELL> </LATTICEGRAPH> </LATTICES>
It works perfect for L=2 (6 sites), but I cant obtain correct magnetization curve for L=3 (9 sites) or L= 4 (12 sites) etc. Would you be so kind to explain me why it works well for small chain and worse for slightly larger chain?
Best regards,
Olesia Krupnitska