About the existence of the exotic molecular ions $(HeH{)}^{2+}$ and $H{e}_2^{3+}$ in a strong magnetic field

Abstract

The Coulombic systems $(\al p e)$ and $(\al\al e)$, $(\al p p e)$, $(\al \al p e)$ and $(L{i}^{3+}L{i}^{3+}e)$ placed in a magnetic field $B\gtrsim 10^{11}G$ are studied. It is demonstrated a theoretical existence of the exotic ion $(HeH{)}^{2+}$ for $B\gtrsim 5\times 10^{12}G$ in parallel configuration (the magnetic field is directed along internuclear axis) as optimal as well as its excited states $1\pi ,1\delta$. As for the exotic ion ${He}_2^{3+}$ it is shown that in spite of strong electrostatic repulsion of $\al-$particles this ion can also exist for $B\gtrsim 100a.u.(=2.35\times 10^{11}G)$ in parallel configuration as optimal in the states $1\si_g$ (ground state), $1{\pi }_u,1{\delta }_g$. Upon appearance both ions are unstable towards dissociation with $H{e}^{+}$ in the final state but with very large lifetime. However, at $B\gtrsim 10000$ a.u. the ion $(HeH{)}^{2+}$ becomes stable, while at $B\gtrsim 1000$ a.u. the ion ${He}_2^{3+}$ becomes stable. With a magnetic field growth, both exotic ions become more and more tightly bound and compact, their lowest rotational and vibrational energies grow. At the edge of applicability of non-relativistic approximation, $B\sim 4.414\times 10^{13}$ G, there are indications that three more exotic linear ions $(H-He-H{)}^{3+}$, $(He-H-He{)}^{4+}$ and even $L{i}_2^{5+}$ in parallel configuration may also occur.

24 pages, 11 Figures, 7 Tables, revtex4 (preprint single column format). The text is slightly modified. To Table 4 a complete set of the lowest rotational energies for the ${He}_2^{3+}$ is added. Also a behavior of the rotational and vibrational energies viz magnetic field is briefly discussed