Possible “umbrella”-like antimagnetic rotation mode in odd-A Pd101,103 and even-even Pd102,104

The tilted-axis cranking model based on covariant density functional theory is used to study the candidate antimagnetic rotation (AMR) bands in $^{101,102,103,104}\mathrm{Pd}$. The experimental energy spectra and $B(E2)$ values are reproduced well in the self-consistent and microscopic calculations. By investigating microscopically the composition and orientation of angular momentum, an ``umbrella''-like antimagnetic rotation (UAMR) mode resulting from the coupling of four ${g}_{9/2}$ proton holes to neutron particles is clearly illustrated for the first time.