Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Transport through a double quantum dot system with non-collinearly
  polarized leads   We investigate linear and non-linear transport in a double quantum dot system
weakly coupled to spin-polarized leads.
  In the linear regime, the conductance as well as the non-equilibrium spin
accumulation are evaluated in analytic form. The conductance as a function of
the gate voltage exhibits four peaks of different height, with mirror symmetry
with respect to the charge neutrality point. As the polarization angle is
varied, the position and shape of the peaks changes in a characteristic way
which preserves the electron-hole symmetry of the problem. In the nonlinear
regime negative differential conductance features occur for non collinear
magnetisations of the leads. In the considered sequential tunneling limit, the
tunneling magneto resistance (TMR) is always positive with a characteristic
gate voltage dependence for non-collinear magnetization. If a magnetic field is
added to the system, the TMR can become negative.

8
The categories of this paper are: hep-ex
27
The categories of this paper are: comp-gas
3
The categories of this paper are: physics
9
The categories of this paper are: nlin
23
The categories of this paper are: solv-int
35
The categories of this paper are: mtrl-th
18
The categories of this paper are: econ
7
The categories of this paper are: hep-th
34
The categories of this paper are: chem-ph
11
The categories of this paper are: hep-lat
33
The categories of this paper are: plasm-ph
20
The categories of this paper are: acc-phys
22
The categories of this paper are: chao-dyn
24
The categories of this paper are: dg-ga
37
The categories of this paper are: supr-con
15
The categories of this paper are: nucl-ex