Strain tuning of unconventional Zeeman effect in ZrTe5

In condensed matter systems, while Zeeman effect has been extensively studied over the past decades, its connection to band  topology has emerged only recently. Besides splitting the spin-degenerate Fermi surface,  Zeeman effect also induces non-trivial Berry phase which is dependent on the band structure. Here we demonstrate the strain tuning of unconventional Zeeman effect in ZrTe5 and its impact on the amplitude of the Shubnikov de Haas (SdH) oscillations in 3D Dirac semimetal ZrTe5. Varying the uniaxial strain, a strong TI to weak TI transition is identified. The dependence of the SdH oscillation amplitude on Fermi energy and Dirac mass gap, both tunable through the strain, is analyzed and compared with the quantum oscillation theory.  It is found that the Berry curvature induced by Zeeman effect is a critical factor in modeling the SdH oscillations in such topological materials.