Negative magnetoresistance component and supercurrent diode effect in microstructured NbGe 2 chiral crystals

${\mathrm{NbGe}}₂$ is a superconductor with a chiral crystalline structure such that nontrivial topology may play an important role. Here, we carry out magneto-transport study on microstructured ${\mathrm{NbGe}}₂$. We develop a special recipe that substantially minimizes the influence of the microstructuring-induced surface layer. The fabricated ${\mathrm{NbGe}}₂$ samples show a negative magneto-resistance component at temperatures below 30 K when the magnetic field is parallel to the applied current, akin to the chiral anomaly observed in Weyl semimetals. Furthermore, we realize additional two-dimensional superconductivity by bombarding the ${\mathrm{NbGe}}₂$ surface with gallium ion beam. This surface layer exhibits the supercurrent diode effect under an in-plane magnetic field. Our results demonstrate that microstructuring may pave the way toward exploring exotic properties of such a chiral superconductor.