Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Transient spin current under a thermal switch   In this work, we explore the possibility of enhancing a spin current under a
thermal switch, i.e., connecting the central transport region to two leads in
individual thermal equilibrium abruptly. Using the nonequilibrium Green's
function method for the transient spin current, we obtain a closed-form
solution, which is applicable in the whole nonlinear quantum transport regime
with a significant reduction of computational complexity. Furthermore, we
perform a model calculation on a single-level quantum dot with Lorentzian
linewidth. It shows that the transient spin current may vary spatially, causing
spin accumulation or depletion in the central region. Moreover, general
enhancement of the spin current in the transient regime is observed. In
particular, the in-plane components of the transient spin current may increase
by 2-3 orders of magnitude compared to the steady-state thermoelectric spin
current under a temperature difference of 30 K. Our research demonstrates that
ultrafast enhancement of spin currents can be effectively achieved by thermal
switches.

11
The categories of this paper are: hep-lat
17
The categories of this paper are: q-fin
10
The categories of this paper are: q-bio
2
The categories of this paper are: math
6
The categories of this paper are: astro-ph
18
The categories of this paper are: econ
29
The categories of this paper are: funct-an
16
The categories of this paper are: stat
20
The categories of this paper are: acc-phys
32
The categories of this paper are: atom-ph
7
The categories of this paper are: hep-th
33
The categories of this paper are: plasm-ph
19
The categories of this paper are: eess
36
The categories of this paper are: cmp-lg
28
The categories of this paper are: alg-geom
31
The categories of this paper are: ao-sci