Trapping electrons in electrostatic traps over the surface of He-4

摘要

We have observed trapping of electrons in an electrostatic trap formed over the surface of liquid He-4. These electrons are detected by a Single Electron Transistor located at the center of the trap. We can trap any desired number of electrons between 1 and similar to 30. By repeatedly (similar to 10(3)-10(4) times) putting a single electron into the trap and lowering the electrostatic barrier of the trap, we can measure the effective temperature of the electron and the time of its thermalisation after heating up by incoherent radiation.