Figure 4: Correlation between negative MR and ferromagnetism.
From: Electrically tuned magnetic order and magnetoresistance in a topological insulator
(a,b) Temperature dependence of MR at two representative gate voltages. (a) Vg=−15 V. As the EF cuts through the bulk valence band, negative MR is observed over all temperature. Each curve is offset by 1.5% for clarity. (b) Vg=2 V. When the EF is tuned into the bulk gap, WAL begin to take charge the transport and WAL is observed above TC. Each curve is offset by 1% for clarity. (c,d) The position of EF at the two gate voltages Vg=−15 V (c) and Vg=+2 V (d). (e) Colour plot of the relative change of MR at μ0H=0.3 T. Negative MR is more pronounced in the regime of high Vg and low temperature, which are favourable for the enhancement of ferromagnetism.
