 Transverse magnetic focusing

A magnetic field curves ballistic carrier trajectories between an injector and a collector. For openings separated along a specular edge by $L$, peaks occur near $L=2j{r}_c$ with $r_c=\hslash k_F/(e|B|)$, giving $|B_j|=2j\hslash k_F/(eL)$. Field polarity and carrier sign select the connection direction. Electron phase coherence can produce fine structure but is not required for the basic semiclassical focusing geometry.