  The transient tunneling current of single electron transistors (SETs) is
theoretically investigated. The time-dependent current formula given by Jauho,
Wingreen and Meir [Phys. Rev. B 50, 5528 (1994)] is applied to study the
temperature effect on the transient current through a single quantum dot
embedded into asymmetry barrier. It is found that the tunneling rate ratio
significantly influences the feature of transient current. Finally, the
oscillation structures on the exponential growth transient current of single
hole transistors composed of germanium quantum dots is analyzed.
