Fabrication and magnetotransport measurements of ZrSiSe/CrGeTe3 heterostructures*

Band crossings of topological materials are protected by crystal symmetry and time reversal symmetry. Breaking time reversal symmetry splits the Dirac cone into a pair of Weyl cones creating a new quantum anomalous Hall insulator state. We report the fabrication and transport measurements of ZrSiSe/CrGeTe3 heterostructures in which Hall bars are fabricated on thin flakes of ZrSiSe, an exfoliatable topological semimetal. To break time reversal symmetry, a few-layer flake of the 2D ferromagnet CrGeTe3 is transferred onto the ZrSiSe. Finally, the ZrSiSe is gated from the top using FeSe with an hBN insulation layer, which also prevents oxidation of the ZrSiSe. Transport measurements of ZrSiSe show quantum oscillations with frequency of 210 T and giant magnetoresistance of 1500%. We will discuss ongoing experiments as a function of gate voltage and compare heterostructures with and without the ferromagnetic layer.