Odd-even staggering in simple models of metal clusters

Proton-neutron (p − n) interactions and their various aspects in N ≈ Z nuclei of g 9/2 -and f 7/2 subshell are studied using a schematic model interaction with four force parameters proposed recently. It is shown that the model interaction well reproduces observed physical quantities: the double differences of binding energies, symmetry energy, Wigner energy, odd-even mass difference and separation energy, which testifies to the reliability of the model interaction and its p−n interactions. First of all, the double differences of binding energies are used for probing the p-n interactions. The analysis reveals different contributions of the isoscalar and isovector p − n pairing interactions to two types of double differences of binding energies, and also indicates the importance of a unique form of isoscalar p − n pairing force with all J components. Next, it is shown that this p-n force is closely related to the symmetry energy and the Wigner energy. Other calculations demonstrate the significant roles of p − n interactions in the odd-even mass difference and in the separation energy at N = Z. PACS number(s):

show abstract

“…1(b) combined with the relations (24) and (26) suggests that in a wide-range view the force strength k 0 might have 1/A dependence…”

Section: Double Differences Of Binding Energies and P-n Interactmentioning

confidence: 99%

“…An ordinary estimation of the neutron or proton pairing gap from the OEMD is not applicable to these nuclei. On the other hand, it has recently been discussed that the OEMD in light nuclei is affected by deformation as well as J = 0 pairing correlation [24][25][26].…”

Section: Introductionmentioning

confidence: 99%

Proton-neutron interactions inN≈Znuclei

Kaneko

Hasegawa

1999

Phys. Rev. C

View full text Add to dashboard Cite

show abstract

“…The original spherical model [14] has, over the years, been developed to include background deformations [15,16] and in this way, it has been possible to account for the fine structure in the measured electronic properties as well. Just recently, Manninen et al [8] analyzed the existence of the odd-even alternation using different transparent cluster models, such as the Hiickel model, the triaxial harmonic oscillator and the rectangular box. Their study and other theoretical investigations have made it clear that the origin of the odd-even alternation is spin pairing in two electron cluster levels.…”

Section: Introductionmentioning

confidence: 99%

“…The alkali clusters have been investigated using ab initio [3] and density functional I-4-6] as well as simple tight-binding Hiickel calculations [7,8]. Also for copper and silver clusters, density functional [9, 1t3] as well as ab initio [11,12] calculations have been reported.…”

Section: Introductionmentioning

confidence: 99%

Analysis of the odd-even alternation in simple metal clusters

Grönbeck

Rosén²

1996

Z Phys D - Atoms, Molecules and Clusters

View full text Add to dashboard Cite

Abstract.A set of MO-LCAO calculations within the LSDA formalism has been performed for the analysis of the odd-even alternation in simple metal clusters. Electronic properties, including ionization potentials and partial density of states analyses were evaluated for clusters of Na, K, Cu and Ag ranging from two to nine atoms. The present study focus on the differences in magnitude of the odd-even alternation, which is attributed to the electronic level separation close to the Fermi level of the clusters. For the coinage metals, the hybridization between s, d and p states is shown to strongly influence the alternation, reducing the magnitude for copper to about the same value as for silver. The small reduction of the alternation magnitude due to a finite spin density for the odd clusters is also investigated by means of comparative LDA calculations.

show abstract

“…In small metal clusters, OES is believed to be mainly due to the non-spherical shape of the underlying mean field [6][7][8] and, thus far, neither the empirical evidence nor the theoretical calculations [9] support the presence of superconductive correlations in metal clusters. In superconducting grains, on the other hand, OES is believed to be predominantly due to a blocking effect caused by the presence of an odd electron (see Refs.…”

Section: Introductionmentioning

confidence: 99%

Odd-even staggering of binding energies as a consequence of pairing and mean-field effects

et al. 2001

View full text Add to dashboard Cite

Odd-even staggering of binding energies is studied in finite fermion systems with pairing correlations. We discuss contributions of the pairing and mean-field to the staggering, and we construct the binding-energy filters which measure the magnitude of pairing correlations and the effective singleparticle spacings in a given system The analysis is based on studying several exactly-solvable manybody Hamiltonians as well as on the analytical formulas that can be applied in the weak and strong pairing limits. PACS number(s): 21.10. Dr, 21.10.Pc, 21.60.Jz, 71.15.Mb

show abstract

Odd-even staggering in simple models of metal clusters

Cited by 55 publications

References 20 publications

Proton-neutron interactions inN≈Znuclei

Proton-neutron interactions inN≈Znuclei

Analysis of the odd-even alternation in simple metal clusters

Odd-even staggering of binding energies as a consequence of pairing and mean-field effects

Contact Info

Product

Resources

About