From: hackbard Date: Tue, 13 May 2008 17:31:51 +0000 (+0200) Subject: final X-Git-Url: https://hackdaworld.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=82e203acc6d8f125b12df53e5697d5df0875f0e3;p=lectures%2Flatex.git final --- diff --git a/solid_state_physics/tutorial/2_02.tex b/solid_state_physics/tutorial/2_02.tex index 5f280f0..8787db5 100644 --- a/solid_state_physics/tutorial/2_02.tex +++ b/solid_state_physics/tutorial/2_02.tex @@ -66,7 +66,7 @@ and $\lambda$ is the London penetration depth. \section{Penetration of the magnetic field into a type 1 superconductor} In the following, the behaviour of the magnetic field ${\bf B}_s({\bf r})$ in the surface layer of a superconductor is calculated. -In the superconductor the magnetic field is given by +Inside the superconductor the magnetic field is given by \[ {\bf B}_s=\mu_0 \left({\bf H}_a + {\bf M}_s\right) \] @@ -82,7 +82,9 @@ ${\bf M}_s$ is the magnetization of the superconductor. magnetic field inside the superconductor? Apply the second London equation $\nabla \times {\bf j}_s=-{\bf B}_s/\Lambda$ + with $\lambda=\sqrt{\Lambda/\mu_0}$ relating the supercurrent to the magnetic field. + \item Consider a superconducting half space. The interface of the superconductor ($x>0$) and the vacuum ($x<0$) is located at $x=0$. A magnetic field ${\bf B}_a=\mu_0 H_a {\bf e}_z$ @@ -90,7 +92,7 @@ ${\bf M}_s$ is the magnetization of the superconductor. Calculate and sketch the decay of ${\bf B}_s=B_{s_z}(x) {\bf e}_x$ in the superconductor. - Introduce the London penetration depth $\lambda=\sqrt{\Lambda/\mu_0}$. + Introduce the London penetration depth $\lambda$. \item Out of this, calculate the screening current density ${\bf j}_s$. What is the direction of the current? Calculate the value of ${\bf j}_s$ at the interface?