Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Orbital and spin contributions to the $g$-tensors in metal nanoparticles   We present a theoretical study of the mesoscopic fluctuations of $g$-tensors
in a metal nanoparticle. The calculations were performed using a semi-realistic
tight-binding model, which contains both spin and orbital contributions to the
$g$-tensors. The results depend on the product of the spin-orbit scattering
time $\tau_{\textrm{\small so}}$ and the mean-level spacing $\delta$, but are
otherwise weakly affected by the specific shape of a {\it generic}
nanoparticle. We find that the spin contribution to the $g$-tensors agrees with
Random Matrix Theory (RMT) predictions. On the other hand, in the strong
spin-orbit coupling limit $\delta \tau_{\textrm{\small so}}/\hbar \to 0$, the
orbital contribution depends crucially on the space character of the
quasi-particle wavefunctions: it levels off at a small value for states of $d$
character but is strongly enhanced for states of $sp$ character. Our numerical
results demonstrate that when orbital coupling to the field is included, RMT
predictions overestimate the typical $g$-factor of orbitals that have dominant
$d$-character. This finding points to a possible source of the puzzling
discrepancy between theory and experiment.

27
The categories of this paper are: comp-gas
35
The categories of this paper are: mtrl-th
24
The categories of this paper are: dg-ga
9
The categories of this paper are: nlin
15
The categories of this paper are: nucl-ex
32
The categories of this paper are: atom-ph
30
The categories of this paper are: q-alg
3
The categories of this paper are: physics
34
The categories of this paper are: chem-ph
28
The categories of this paper are: alg-geom
26
The categories of this paper are: bayes-an
14
The categories of this paper are: math-ph
23
The categories of this paper are: solv-int
16
The categories of this paper are: stat
29
The categories of this paper are: funct-an
21
The categories of this paper are: adap-org