Recent content by hesky

thanks!

Ohno Potential is modeled by v(r)=\frac{U}{\alpha ^{2}r^{2}+1}. U and \alpha are constants. I try to Fourier transform it V(q)=\int V(r) e^{iqr\cos \theta}r^{2} \sin \theta d \phi d \theta dr It gives V(q) = 2 \pi U \int \frac {r \sin qr}{\sqrt{\alpha ^{2} r^{2}+1}} dr The...

Just put all the operators, and then take anti-commutation relations several times \left \langle i|c^+_k c_l|i \right \rangle=\delta_{kl} n_i \left \langle i|c_k c^+_l|i \right \rangle=\delta_{kl} (1-n_i) \langle\Psi^f|H|0\rangle=\sum_{k,k'} Z^{n*}_{k_{c},k_v}\langle...

http://flex.phys.tohoku.ac.jp/~rsaito/rsj/j1180.pdf

Please help me, I need to derive exciton-photon interaction. Here, we are using second quantization. Please refer to this paper http://prb.aps.org/abstract/PRB/v75/i3/e035405 Hamiltonian of electron-photon is H_{el-op}=\sum_k D_k c^+_{kc}c_{kv}(a+a^+) c^+_{kc}c_{kv} are creation of...

Thank you very much guyingfei. I'll try it

I had a task from my supervisor, graphene layer has 2 Carbon atoms per unit cell. What will happen if the atoms are replaced by one atom Boron and one atom Nitrogen? Will we found an open band gap? Would you please inform me any literature concerning it?