Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Pulsed electron spin resonance spectroscopy in the Purcell regime   When spin relaxation is governed by spontaneous emission of a photon into the
resonator used for signal detection (the Purcell effect), the relaxation time
$T_1$ depends on the spin-resonator frequency detuning $\delta$ and coupling
constant $g$. We analyze the consequences of this unusual dependence for the
amplitude and temporal shape of a spin-echo in a number of different
experimental situations. When the coupling $g$ is distributed inhomogeneously,
we find that the effective spin-echo relaxation time measured in a saturation
recovery sequence strongly depends on the parameters of the detection echo.
When the spin linewidth is larger than the resonator bandwidth, the Fourier
components of the echo relax with different characteristic times, which implies
that the temporal shape of the echo becomes dependent on the repetition time of
the experiment. We provide experimental evidence of these effects with an
ensemble of donor spins in silicon at millikelvin temperatures measured by a
superconducting micro-resonator.

29
The categories of this paper are: funct-an
35
The categories of this paper are: mtrl-th
8
The categories of this paper are: hep-ex
31
The categories of this paper are: ao-sci
14
The categories of this paper are: math-ph
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
0
The categories of this paper are: hep-ph
30
The categories of this paper are: q-alg
24
The categories of this paper are: dg-ga
13
The categories of this paper are: quant-ph
23
The categories of this paper are: solv-int
11
The categories of this paper are: hep-lat
16
The categories of this paper are: stat
33
The categories of this paper are: plasm-ph