1202.3237 (Andreas Wild et al.)

Few electron double quantum dot in an isotopically purified $^{28}$Si
quantum well    [PDF]

Andreas Wild, Johannes Kierig, Jürgen Sailer, Joel Ager III, Eugene Haller, Gerhard Abstreiter, Stefan Ludwig, Dominique Bougeard

We present a few electron double quantum dot (QD) device defined in an
isotopically purified $^{28}$Si quantum well (QW). An electron mobility of $5.5
\cdot 10^4 cm^2(Vs)^{-1}$ is observed in the QW which is the highest mobility
ever reported for a 2D 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.

View original: http://arxiv.org/abs/1202.3237