Fig. 1

Influence of the DOS. AP and P state. a, FM | FM. Since the individual currents cancel out, the Seebeck effect and TMS ratio are small. b, FMSC | HM. In the AP state electrons only travel above μ. In the P state electrons only travel below μ. This is optimal for generating large Seebeck coefficients with opposite sign. c, Heusler | HM. In the AP state the transport is similar to the FMSC | HM MTJ. In the P state electrons travel above and below μ. Hence, the Seebeck effect in the P state is small, while it is large in the AP state, leading to a large TMS ratio. d–f, The DOS obtained from DFT for Heusler compounds with theoretically predicted high TMS