Recent content by Enialis

Ok, but that relation does not help me so much. In this example I need to solve an integral of the form: \int_0^a J_{m+1}(kr)J_{m-1}(kr) r\,dr I found only two useful formulas (that include the result of eq. 53): \int J_m(kx)J_m(lx)x...

For the divergence of the field I found: \nabla\cdot\vet{A}= kJ_m(kr)\cos(\phi) using recursive formulas for the Bessel derivatives. I still need help for the integrals, in particular does the bessel functions have particular orthogonality relation that admit to solve: \int J_m(x) J_n(x)...

I need to solve this general problem. Let's consider the following vector field in cylindrical coordinates: \vec{A}=-J'_m(kr)\cos(\phi)\hat{\rho}+\frac{m^2}{k}\frac{J_m(kr)}{r}\sin(\phi)\hat{\phi}+0\hat{z} where m is an integer, and k could satisfy to: J_m(ka)=0 or J_m'(ka)=0 with a real. (the...

Effective mass and bands in semiconductors In the study of the basic semiconductor physics devices we usually draw flat bands without taking into account the spatial dependence of them. Now why is it correct? I suppose that the "real band diagram" informations are included into the effective...

Homework Statement I am trying to solve a problem of 1D electron system. Given a,a^\dagger,b,b^\dagger annihilation and creation operator which satisfy the fermion commutation relations diagonalize the following hamiltonian...