Electron microscope

摘要

An electron microscope which utilizes a polarized electron beam and can obtain a high contrast image of a sample is provided. The microscope includes: a laser; a polarization apparatus that polarizes a laser beam into a circularly polarized laser beam; a semiconductor photocathode that is provided with a strained superlattice semiconductor layer and generates a polarized electron beam when irradiated with the circularly polarized laser beam; a transmission electron microscope that utilizes the polarized electron beam; an electron beam intensity distribution recording apparatus arranged at a face reached by the polarized electron beam that has transmitted through the sample. An electron beam intensity distribution recording apparatus records an intensity distribution before and after the polarization of the electron beam is reversed, and a difference acquisition apparatus calculates a difference therebetween.

主权项

1. An electron microscope that uses an electron beam of which spin direction is polarized, and of which polarized spin direction reverses over time, comprising:
a laser; a polarization apparatus that polarizes a laser beam generated by the laser into a circularly polarized laser beam and that is capable of reversing the direction of the circular polarization over time; a semiconductor photocathode that is provided with a strained superlattice semiconductor layer and generates a polarized electron beam of which spin direction is polarized, when irradiated with the circularly polarized laser beam polarized by the polarization apparatus; a transmission electron microscope that utilizes the polarized electron beam generated by the semiconductor photocathode; an electron beam intensity distribution recording apparatus that is arranged at a face reached by the polarized electron beam that has transmitted through a sample; a reversal instruction apparatus that sends a signal to the polarization apparatus to reverse the direction of the circular polarization, and also sends in synchronization therewith a signal to the electron beam intensity distribution recording apparatus; and a difference acquisition apparatus that calculates a difference between an electron beam intensity distribution recorded by the electron beam intensity distribution recording apparatus before the reversal instruction apparatus sends the signal, and an electron beam intensity distribution recorded by the electron beam intensity distribution recording apparatus after the reversal instruction apparatus sends the signal.