  Photon helicity-dependent photocurrent is measured at zero magnetic field on
a device based on an ensemble of InGaAs/GaAs quantum dots that are embedded
into a GaAs-based p-i-n diode. Our main goal is to take advantage of the long
electron spin relaxation time expected in these nano-objects. In these
experiments, no external magnetic field is required thanks to the use of an
ultrathin magnetic CoFeB/MgO electrode, presenting perpendicular magnetic
anisotropy (PMA). We observe a clear asymmetry of the photocurrent measured
under respective right and left polarized light that follows the hysteresis of
the magnetic layer. The amplitude of this asymmetry at zero magnetic field
decreases with increasing temperatures and can be controlled with the bias.
Polarization-resolved photoluminescence is detected in parallel while the
device is operated as a photodetector. This demonstrates the multifunctional
capabilities of the device and gives valuable insights into the spin relaxation
of the electrons in the quantum dots.
