Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Ultrafast laser-triggered emission from hafnium carbide tips   Electron emission from hafnium carbide (HfC) field emission tips induced by a
sub-10 fs, 150 MHz repetition rate Ti:sapphire laser is studied. Two-photon
emission is observed at low power with a moderate electric bias field applied
to the tips. As the bias field and/or laser power is increased, the average
current becomes dominated by thermally-enhanced field emission due to laser
heating: both the low thermal conductivity of HfC and the laser's high
repetition rate can lead to a temperature rise of several hundred Kelvin at the
tip apex. The contribution of current from a thermal transient at times shorter
than the electron-phonon coupling time is considered in the context of the
two-temperature model. Under the conditions of this experiment, the integrated
current from the thermal transient is shown to be negligible in comparison with
the two-photon emission. A finite element model of the laser heating and
thermal conduction supports these conclusions and is also used to compare the
nature of thermal effects in HfC, tungsten, and gold tips.

0
The categories of this paper are: hep-ph
27
The categories of this paper are: comp-gas
37
The categories of this paper are: supr-con
6
The categories of this paper are: astro-ph
19
The categories of this paper are: eess
16
The categories of this paper are: stat
10
The categories of this paper are: q-bio
8
The categories of this paper are: hep-ex
24
The categories of this paper are: dg-ga
35
The categories of this paper are: mtrl-th
11
The categories of this paper are: hep-lat
1
The categories of this paper are: cs
23
The categories of this paper are: solv-int
7
The categories of this paper are: hep-th
36
The categories of this paper are: cmp-lg
2
The categories of this paper are: math