text: measurements were performed on beamline I06 at the 
  Diamond Light Source, and on beamline 4.0.2 at the Ad- 
  vanced Light Source. Total-electron yield (TEY) and 
  ﬂuorescence yield (FY) were monitored simultaneously 
  using the sample drain current and the photocurrent of a 
  diode mounted at 90◦ to the incident beam, respectively. 
  were 
  magnetometry 
  and 
  control Fe/GaAs(001) 
  ﬁrst 
  on 
  performed 
  grown under 
  the 
  samples, 
  (Ga,Mn)As/GaAs(001) 
  same conditions as the bilayers, 
  to determine the 
  magnetic anisotropies of the individual layers and the 
  Curie temperature of the (Ga,Mn)As layer. The Fe ﬁlm 
  has a uniaxial magnetic anisotropy with easy axis along 
  the [110] orientation, similar to previous studies6. For 
  the (Ga,Mn)As control sample, there is a competition 
  between cubic and uniaxial magnetic anisotropies, with 
  the former dominant at low temperatures and favoring 
  easy axes along the in-plane h100i orientations, and the 
  latter dominant close to TC (∼35 K) giving an easy axis 
  along the [1¯10] orientation. Figure 1 shows [110] magne- 
  tization versus temperature curves and low temperature 
  hysteresis loops for a bilayer ﬁlm containing a 20 nm 
  thick (Ga,Mn)As layer. The total remnant moment of 
  the bilayer ﬁlm decreases on cooling under zero magnetic 
  ﬁeld below the TC of the (Ga,Mn)As, indicating that 
  this layer aligns antiparallel to the Fe magnetization 
  at zero ﬁeld. The hysteresis curve shows a two-step 
  magnetization reversal, indicating diﬀerent behavior of 
  the Fe and (Ga,Mn)As layers, with the smaller loop 
  attributed to the dilute moment (Ga,Mn)As ﬁlm. The 
  minor hysteresis loop shown in Fig. 1 clearly shows a 
  shift from zero ﬁeld by a bias ﬁeld HE, indicating that 
  the Fe layer induces an exchange bias in the magnetic 
  semiconductor. The shape and size of the minor loop 
  is in agreement with the hysteresis loop for the control 
  (Ga,Mn)As sample, also shown in Fig. 1. This strongly 
  indicates that the exchange bias aﬀects the whole of the 
  (Ga,Mn)As layer in the bilayer sample. 
  
  SQUID 