Fig. 4b: Temperature dependence of the USMR-SHG, and UDM-SHG signals, and their ratio to exclude experimental artifacts related to the drift of the overall signal due to thermal contractions. Temperature (K) / SHG field (USMR) / SHG field (UDM) / SHG USMR/SHG UDM 5 1.96561E-7 0.00122 4.92247E-4 50 2.04718E-7 0.00117 4.92247E-4 100 2.97385E-7 0.00115 4.92247E-4 150 3.87048E-7 0.00115 4.92247E-4 200 4.25268E-7 0.00114 4.92247E-4 300 5.23678E-7 0.00108 4.92247E-4