Few electron double quantum dot in an isotopically purified 28 Si quantum well

• Published in: Applied physics letters Vol. 100; no. 14; pp. 143110 - 143110-4
• Main Authors: Wild, A., Kierig, J., Sailer, J., Ager, J. W., Haller, E. E., Abstreiter, G., Ludwig, S., Bougeard, D.
• Format: Journal Article
• Published: American Institute of Physics 06-04-2012
• ISSN: 0003-6951; 1077-3118
• DOI: 10.1063/1.3701588

We present a few electron double quantum dot device defined in an isotopically purified
28
Si quantum well (QW). An electron mobility of
5
.
5
·
10
4
cm
2
(
Vs
)
-
1
is observed in the QW, which is the highest mobility ever reported for a two-dimensional electron system in
28
Si. The residual concentration of
29
Si nuclei in the
28
Si QW is lower than
10
3
ppm
, at the verge where the hyperfine interaction is theoretically no longer expected to dominantly limit the
T
2
spin dephasing time. We also demonstrate a complete suppression of hysteretic gate behavior and charge noise using a negatively biased global top gate.