A bizarre state of confined He-3

Atoms under various types of external confinements have been scrutinized by theorists for many years now. Here, we focus on a He-3 atom whose 1s² shell is known to undergo a tiny hyperfine spin-splitting: 1s² →1s↑1s↓. We treat the spin-split He-3 within the known spin-polarized Hartree-Fock approximation which we modify by the incorporation of a spin-dependent adjustable parameter to model the hyperfine splitting. We place He-3 inside a spherical potential box of a height U₀, width △ (U₀ = 5 Ry, △ = 5 a.u., as a case study), and an adjustable inner radius R₀.The resultant atomic potential becomes a double-well potential with the inner and outer wells being separated by about 5 a.u. We model the pressure on He-3 by narrowing the inner radius R₀. We find that, at R₀ ≤ 0.85 a.u., the 1s↓-electron migrates into an outer well. The 1s↑-electron remains in the inner well as long as R₀ > 0.4 a.u. We, thus, unravel a possibility of creating a bizarre state of He-3 with the much different orbital radii and energies of the 1s↑- and 1s↓ electrons. At R₀'s ≤ 0.4 a.u. both electrons reside in the outer well, far away from the nucleus, and He-3 turns into a novel type of a low-n (n = 1) and low-I (I = 0) "Rydberg" atom.