Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Vortex quantum tunnelling versus thermal activation in ultrathin
  superconducting nanoislands   We consider two possible mechanisms for single-vortex fluctuative entry/exit
through the surface barrier in ultrathin superconducting disk-shaped
nanoislands made of Pb and consisting of just few monoatomic layers, which can
be fabricated using modern techniques. We estimate tunnelling probabilities and
establish criteria for the crossover between these two mechanisms depending on
magnetic field and system sizes. For the case of vortex entry, quantum
tunnelling dominates on the major part of the temperature/flux phase diagram.
For the case of vortex exit, thermal activation turns out to be more probable.
This nontrivial result is due to the subtle balance between the barrier height
and width, which determine rates of the thermal activation and quantum
tunneling, respectively.

7
The categories of this paper are: hep-th
23
The categories of this paper are: solv-int
13
The categories of this paper are: quant-ph
28
The categories of this paper are: alg-geom
17
The categories of this paper are: q-fin
10
The categories of this paper are: q-bio
26
The categories of this paper are: bayes-an
20
The categories of this paper are: acc-phys
18
The categories of this paper are: econ
34
The categories of this paper are: chem-ph
30
The categories of this paper are: q-alg
2
The categories of this paper are: math
24
The categories of this paper are: dg-ga
3
The categories of this paper are: physics
35
The categories of this paper are: mtrl-th
14
The categories of this paper are: math-ph