Quantum Coherent Electron Devices 



Staffs:	  K. Furuya    Y. Miyamoto  M. Suhara
Research fellow:       M. Gault
Students: Y.C. Kang    H. Matsuura  N. Kikegawa  R. Koizumi  N. Machida
	  R. Takemura  H. Hongo     T. Otake     M. Katoh    H. Tanaka

A novel ultra high-speed transistor utilizing high-velocity and wave properties of the ballistic electron was proposed and studied from the viewpoint of (1)ballistic transport in GaInAs/InP, in particular, the wave nature of the hot electron, (2)device concept using the wave-nature of the hot electron, and (3)nanostructure fabrication technology.

Results obtained up to now are as follows.


  1. Estimation of phase coherence length of hot electron: To evaluate the phase coherent length of hot electrons using resonant tunneling diodes (RTD), we theoretically analyzed the relation between resonant energy width and coherent length. Phase coherent length was estimated by the width of resonant energy level. To study the coherence of hot electron, GaInAs/InP resonant tunneling diodes (RTD) were fabricated. The resonant level widths were measured experimentally and we can separate the each cause of the resonant level broadening by investigate structure dependency. The coherent transverse length of hot electron in GaInAs was estimated as 80 to 120 nm at temperature 4.2K.