Relativistic energy loss and induced photon emission in the interaction of a left-handed sphere with an external electron beam

Relativistic energy loss and photon emission in the interaction of a coated sphere containing a left-handed material with an external electron beam are studied based on the classical electrodynamics. Both of electric modes and magnetic modes are not only found in the spectra of energy loss and photon emission for different combinations of electron velocity and sphere radius, the new excitation modes can be also observed. Our results show that different excitation modes for the left-hand materials and the structure information of coated sphere can be explored by scanning transmission electron microscopy (STEM).