Recent content by chientewu

Thanks! That makes sense but I still don't understand why this given state is an eigenstate of field operators with eigenvalue being the field amplitudes at some specific position.

Hi, I am studying Peskin's An Introduction To Quantum Field Theory. On the beginning of page 284, the authors say We can turn the field \phi_S(x_1)|\phi_1\rangle=\phi_1(x_1)|\phi_1\rangle. I tried hard to prove this relation but still can't get it right. Could anyone give me some hints? Thanks.

Thanks a lot. My question now becomes "can we call \displaystyle\frac{\pi}{z+i\gamma} it an analytic continuation?", since there is a pole when Im(z)<0.

The following is the problem from Fetter and Walecka (problem 3.7) If f(z) is defined to be the integration of rho(x) * (z-x)^(-1) from -infinity to +infinity. rho is in the following form rho(x)=gamma * ( gamma^2+x^2 )^(-1). Evaluate f(z) explicitly for Im(z)>0 and find its analytic...

Thanks for your quick reply. Now I am confused about your statement "measure it by passing a current through the junction and then measuring the voltage across it." It means we have to pass a current through the junction, otherwise there will be no current? Is it correct. Thanks.

Hi, I am confused about josephson effect. Take SNS for example. If the phase of these two superconductors are different, then there will be a josephson current through the junction. Experimentally, do we measure the current by attach two ends of SNS with a wire? If there is no wire attached...

Hi there, I have a question about Coulomb's Law. Assume there is a uniform sphere charge distribution RHO and I want to know the electric field at some point inside the sphere. I can simply apply Coulomb's Law to find it. However, I worry about the contribution from source point that is...