Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Electron-vibron coupling effects on electron transport via a
  single-molecule magnet   We investigate how the electron-vibron coupling influences electron transport
via an anisotropic magnetic molecule, such as a single-molecule magnet (SMM)
Fe$_4$, by using a model Hamiltonian with parameter values obtained from
density-functional theory (DFT). Magnetic anisotropy parameters, vibrational
energies, and electron-vibron coupling strengths of the Fe$_4$ are computed
using DFT. A giant spin model is applied to the Fe$_4$ with only two charge
states, specifically a neutral state with the total spin $S=5$ and a singly
charged state with $S=9/2$, which is consistent with our DFT result and
experiments on Fe$_4$ single-molecule transistors. In sequential electron
tunneling, we find that the magnetic anisotropy gives rise to new features in
conductance peaks arising from vibrational excitations. In particular, the peak
height shows a strong, unusual dependence on the direction as well as magnitude
of applied B field. The magnetic anisotropy also introduces vibrational
satellite peaks whose position and height are modified with the direction and
magnitude of applied B field. Furthermore, when multiple vibrational modes with
considerable electron-vibron coupling have energies close to one another, a
low-bias current is suppressed, independently of gate voltage and applied B
field, although that is not the case for a single mode with the similar
electron-vibron coupling. In the former case, the conductance peaks reveal a
stronger B-field dependence than in the latter case. The new features appear
because the magnetic anisotropy barrier is of the same order of magnitude as
the energies of vibrational modes with significant electron-vibron coupling.
Our findings clearly show the interesting interplay between magnetic anisotropy
and electron-vibron coupling in electron transport via the Fe$_4$. The similar
behavior can be observed in transport via other anisotropic magnetic molecules.

10
The categories of this paper are: q-bio
29
The categories of this paper are: funct-an
37
The categories of this paper are: supr-con
2
The categories of this paper are: math
26
The categories of this paper are: bayes-an
5
The categories of this paper are: gr-qc
25
The categories of this paper are: patt-sol
28
The categories of this paper are: alg-geom
13
The categories of this paper are: quant-ph
8
The categories of this paper are: hep-ex
3
The categories of this paper are: physics
12
The categories of this paper are: nucl-th
36
The categories of this paper are: cmp-lg
11
The categories of this paper are: hep-lat
24
The categories of this paper are: dg-ga
35
The categories of this paper are: mtrl-th