  We have discovered an unexpected and surprising fact: a 2D axially symmetric
short-range potential contains {\it infinite} number of the levels of negative
energy {\it if one takes into account the spin-orbit (SO) interaction.} For a
shallow well ($m_eU_0R^2/\hbar^2 \ll 1$, where $m_e$ is the effective mass,
$U_0$ and $R$ are the depth and the radius of the well, correspondingly) and
weak SO coupling ($|\alpha|m_eR/\hbar \ll 1$, $\alpha$ is the SO coupling
constant) exactly one two-fold degenerate bound state exists for each value of
the half-integer moment $j=m+1/2$, and the corresponding binding energy $E_m$
extremely rapidly decreases with increasing $m$.
