Large-scale shell model study of the newly found isomer in la 136

The doubly-odd nucleus $^{136}\mathrm{La}$ is theoretically studied in terms of a large-scale shell model. The energy spectrum and transition rates are calculated and compared with the most updated experimental data. The isomerism is investigated for the first ${14}^{+}$ state, which was found to be an isomer in the previous study [Phys. Rev. C 91, 054305 (2015)]. It is found that the ${14}^{+}$ state becomes an isomer due to a band crossing of two bands with completely different configurations. The yrast band with the ($\ensuremath{\nu}{h}_{11/2}^{\ensuremath{-}1}\ensuremath{\bigotimes}\ensuremath{\pi}{h}_{11/2}$) configuration is investigated, revealing a staggering nature in $M1$ transition rates.