Ferromagnetic-electrodes-induced Hall effect in topological Dirac semimetals

We propose an unconventional type of Hall effect in a topological Dirac semimetal with ferromagnetic electrodes. The itself has time-reversal symmetry, whereas attached electrodes break it, causing the large response. This induced is characteristic helical surface/edge states that arise materials such as semimetals or quantum spin insulators. compute conductance/resistance and angle by using lattice model four-terminal geometry. For four electrodes, occurs whether current voltage are ferromagnetic. When spins almost fully polarized, becomes ideal magnetic Weyl semimetals. show robustness against impurities also discuss injection decay problems. response can be used to detect magnetizations two parallel antiparallel.