Lifetime-enhanced transport in silicon due to spin and valley blockade.
We report the observation of lifetime-enhanced transport (LET) based on perpendicular valleys in silicon by transport spectroscopy measurements of a two-electron system in a silicon transistor. The LET is manifested as a peculiar current step in the stability diagram due to a forbidden transition between an excited state and any of the lower energy states due to perpendicular valley (and spin) configurations, offering an additional current path. By employing a detailed temperature dependence study in combination with a rate equation model, we estimate the lifetime of this particular state to exceed 48 ns. The two-electron spin-valley configurations of all relevant confined quantum states in our device were obtained by a large-scale atomistic tight-binding simulation. The LET acts as a signature of the complicated valley physics in silicon: a feature that becomes increasingly important in silicon quantum devices.
Kavli Institute of Nanoscience, Delft University of Technology, The Netherlands. gabriel.lansbergen@lab.ntt.co.jp
G P
GP
Lansbergen
R
R
Rahman
J
J
Verduijn
G C
GC
Tettamanzi
N
N
Collaert
S
S
Biesemans
G
G
Klimeck
L C L
LC
Hollenberg
S
S
Rogge