Evidence for spin–orbit effects in an open ballistic quantum dot

We report on magnetoconductance measurements of an open two-dimensional ballistic cavity in a tilted magnetic field. In agreement with Folk et al. (Phys. Rev. Lett. 86 (2001) 2102), we show that, due to an increasing spin–orbit interaction, the variance of conductance fluctuations decreases when a large in-plane magnetic field is applied. When the magnetic field is applied parallel to the 2DEG, we observe a negative magnetoconductance peak around zero total field, which is reminiscent of the weak antilocalization effect induced by spin–orbit interaction.