“…(25),(A.1) for any value of magnetic field the energy of the branch ǫ = ǫ 2 has the minimum ǫ h) = ǫ crit1 (h) , f Energy spectrum (3) for the magnetic field directed along kx = −ky axis, ϕ h = 3π/4, (a,b) and along kx = ky axis, ϕ h = π/4, (c,d). a,c)h = 0.5 <hc1 = 1.28,hc2 = 1.44; b,d)h = 1.5 >hc1,hc2.…”