  Bound and resonance states of helium atom have been investigated inside a
quantum dot by using explicitly correlated Hylleraas type basis set within the
framework of stabilization method. To be specific, precise energy eigenvalues
of bound 1sns (1Se) [n = 1-6] states and the resonance parameters i.e.
positions and widths of 1Se states due to 2sns [n = 2-5] and 2pnp [n = 2-5]
configuration of confined helium below N = 2 ionization threshold of He+ have
been estimated. The two-parameter (Depth and Width) finite oscillator potential
is used to represent the confining potential representing the quantum dot. It
has been explicitly demonstrated that electronic structure properties become a
sensitive function of the dot size. It is observed from the calculations of
ionization potential that the stability of an impurity ion within quantum dot
may be manipulated by varying the confinement parameters. A possibility of
controlling the autoionization lifetime of doubly excited states of
two-electron ions by tuning the width of the quantum cavity is also discussed
here.
