Negative ions in liquid helium: Existence of new bound states

Sekatskiǐ, S. K.

doi:10.1134/1.567376

Cited by 6 publications

(14 citation statements)

References 11 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…We have not found evidence of the state proposed in Ref. 48 on the basis of a simplified description of the system, where the impurity atom is predicted to reside in the bubble cavity, at a distance of about R / 2 from the center, where the electric field produced by an electron at the center of the bubble would reach its largest value. 48 According to our calculations, instead, once the Ca atom enters the 4 He cavity interface, it is drawn inside toward the center of the bubble, while the extra electron is eventually spherically distributed around it.…”

Section: Resultsmentioning

confidence: 69%

“…48 on the basis of a simplified description of the system, where the impurity atom is predicted to reside in the bubble cavity, at a distance of about R / 2 from the center, where the electric field produced by an electron at the center of the bubble would reach its largest value. 48 According to our calculations, instead, once the Ca atom enters the 4 He cavity interface, it is drawn inside toward the center of the bubble, while the extra electron is eventually spherically distributed around it. Although the trapped Ca − ion described above has a lower energy than the separated neutral Ca and electron bubble pair, it is however a metastable state, the most stable state being the one where the Ca − ion floats above the 4 He surface, being hold to it only by very weak polarization forces.…”

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Negative impurity ions in liquidH4e

2009

View full text Add to dashboard Cite

We present theoretical results, based on zero-temperature density-functional theory, for the formation and properties of a negative impurity ion in bulk liquid 4 He. We first consider Ca which, due to its very low electron affinity, does not easily form a negative ion in vacuum. We show that a neutral Ca atom in bulk liquid 4 He can easily capture a nearby electron bubble leading to the exothermic formation of a Ca − ion trapped inside a spherical cavity of ϳ15 Å radius. The Ca negative ion in bulk 4 He turns out to be a metastable state, the lowest-energy configuration being represented instead by a weakly bound Ca − ion floating over the nearly unperturbed free surface of liquid 4 He. We have computed the threshold negative pressure at which the trapped Ca − ion bubble explodes and we discuss our results in light of recent experimental measurements. We have also considered the possible ion formation in the case of a Ne atom, i.e., an atomic impurity that does not form a negative ion in vacuum. Despite the long-range attraction between the electron bubble and the Ne atom due to polarization forces, in the minimum-energy configuration the electron bubble and the Ne atom rather than merge together remain spatially separated in bulk liquid 4 He, forming a weakly bound state that has no analog in vacuum.

show abstract

Section: Resultsmentioning

confidence: 69%

Section: Resultsmentioning

confidence: 99%

Negative impurity ions in liquidH4e

2009

View full text Add to dashboard Cite

show abstract

“…As an alternative guide geometry we use a thin charged wire in this work, which is spanned through the whole molecular beam apparatus from the rotating nozzle up to the quadrupole mass spectrometer (QMS) that we * Electronic address: Marcel.Mudrich@physik.uni-freiburg.de use as a detector. This concept was proposed by Sekatskii [21,22] and experimentally demonstrated by Loesch [23]. Recently, guiding of polar molecules in surface-based electrostatic potentials has been demonstrated [24,25].…”

Section: Introductionmentioning

confidence: 96%

Guiding slow polar molecules with a charged wire

et al. 2011

View full text Add to dashboard Cite

We demonstrate experimentally the guiding of cold and slow ND3 molecules along a thin charged wire over a distance of ~0.34 m through an entire molecular beam apparatus. Trajectory simulations confirm that both linear and quadratic high-field-seeking Stark states can be efficiently guided from the beam source up to the detector. A density enhancement up to a factor 7 is reached for decelerated beams with velocities ranging down to ~50 m/s generated by the rotating nozzle technique

show abstract

“… 12 , 13 Bound states of electrons attached to superfluid He clusters 16 and floating on a superfluid layer 5 , 17 , 18 have also been studied. Inside of bulk helium, electrons 19 or negative ions 20 are known to form local cavities or ‘bubbles’. The spectra and dynamics of electron bubbles have been analyzed by theory 21 – 23 and experiment.…”

Section: Introductionmentioning

confidence: 99%