Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Ramsey interferometry with generalized one-axis twisting echoes   We consider a large class of Ramsey interferometry protocols which are
enhanced by squeezing and un-squeezing operations before and after a phase
signal is imprinted on the collective spin of $N$ particles. We report an
analytical optimization for any given particle number and strengths of
(un-)squeezing. These results can be applied even when experimentally relevant
decoherence processes during the squeezing and un-squeezing interactions are
included. Noise between the two interactions is however not considered in this
work. This provides a generalized characterization of squeezing echo protocols,
recovering a number of known quantum metrological protocols as local
sensitivity maxima, thereby proving their optimality. We discover a single new
protocol. Its sensitivity enhancement relies on a double inversion of
squeezing. In the general class of echo protocols, the newly found
over-un-twisting protocol is singled out due to its Heisenberg scaling even at
strong collective dephasing.

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The categories of this paper are: chem-ph
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The categories of this paper are: patt-sol
14
The categories of this paper are: math-ph
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The categories of this paper are: atom-ph
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The categories of this paper are: alg-geom
9
The categories of this paper are: nlin
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The categories of this paper are: solv-int
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The categories of this paper are: comp-gas
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The categories of this paper are: dg-ga
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The categories of this paper are: nucl-ex
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The categories of this paper are: chao-dyn
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The categories of this paper are: ao-sci
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The categories of this paper are: hep-lat
4
The categories of this paper are: cond-mat
2
The categories of this paper are: math
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The categories of this paper are: supr-con