Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Ultrastrong magnetic light-matter interaction with cavity mode
  engineering   Magnetic interaction between photons and dipoles is essential in electronics,
sensing, spectroscopy, and quantum computing. However, its weak strength often
requires resonators to confine and store the photons. Here, we present mode
engineering techniques to create resonators with ultrasmall mode volume and
ultrahigh quality factor. In particular, we show that it is possible to achieve
an arbitrarily small mode volume only limited by materials or fabrication with
minimal Q degradation. We compare mode-engineered cavities in a trade-off space
and show that the magnetic interaction can be strengthened more than $10^{16}$
times compared to free space. These methods enable new applications from
high-cooperativity microwave-spin coupling in quantum computing or compact
electron paramagnetic resonance (EPR) sensors to fundamental science such as
dark matter searches.

21
The categories of this paper are: adap-org
1
The categories of this paper are: cs
24
The categories of this paper are: dg-ga
29
The categories of this paper are: funct-an
12
The categories of this paper are: nucl-th
14
The categories of this paper are: math-ph
15
The categories of this paper are: nucl-ex
30
The categories of this paper are: q-alg
17
The categories of this paper are: q-fin
18
The categories of this paper are: econ
22
The categories of this paper are: chao-dyn
33
The categories of this paper are: plasm-ph
20
The categories of this paper are: acc-phys
4
The categories of this paper are: cond-mat
9
The categories of this paper are: nlin
25
The categories of this paper are: patt-sol