hleg1 = legend('SBQ','DBQ','IBQ',4);
set(hleg1,'Interpreter','none');
set(hleg1,'FontSize',15); 

set(gca,'linewidth',2);
set(gca,'FontName','Times New Roman','FontSize',12);
set(gca,'xtick',[16 32 64 128]);

This is with Yuan Cao's help.