$\mathrm{MgT}{\mathrm{i}}_2{\mathrm{O}}_4$ is a spinel superconductor with an optimal $T_{\mathrm{c}}\approx 5$ K recently discovered by employing superlattice engineering. Here, we study the pressure effect on the superconducting properties of $\mathrm{MgT}{\mathrm{i}}_2{\mathrm{O}}_4$ thin films deposited on the ($00l$)-oriented $\mathrm{MgA}{\mathrm{l}}_2{\mathrm{O}}_4$ substrate via measurements of resistance under various pressures up to 12 GPa. We find that the superconducting $T_{\mathrm{c}}$($P$) displays a nonmonotonic evolution, i.e., it first shows a gradual decrease and then exhibits an enhancement above $P_{\mathrm{c}}\sim 3$ GPa, resulting in a V-shaped double dome with two maxima. In addition, our results reveal an interesting correlation between $T_{\mathrm{c}}$ and the normal-state resistance, which exhibits an opposite trend with respect to $T_{\mathrm{c}}$($P$). Moreover, the extracted ${\mu }_0{H}_{c2}$(0) that exceeds the Pauli limit and the obtained large Maki parameter α suggest that the dominant pair-breaking effect is a spin-paramagnetic channel in the measured pressure range. In this work, we not only demonstrate the potential to further raise $T_{\mathrm{c}}$ of the Ti-based spinel superconductors but also offer more insight into the rich physics related to the superconducting mechanism of this family.

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• Pressure effects
• Superconductivity
• Pressure techniques
• Resistivity measurements