Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: High-fidelity indirect readout of trapped-ion hyperfine qubits   We propose and demonstrate a protocol for high-fidelity indirect readout of
trapped ion hyperfine qubits, where the state of a $^9\text{Be}^+$ qubit ion is
mapped to a $^{25}\text{Mg}^+$ readout ion using laser-driven Raman
transitions. By partitioning the $^9\text{Be}^+$ ground state hyperfine
manifold into two subspaces representing the two qubit states and choosing
appropriate laser parameters, the protocol can be made robust to spontaneous
photon scattering errors on the Raman transitions, enabling repetition for
increased readout fidelity. We demonstrate combined readout and back-action
errors for the two subspaces of $1.2^{+1.1}_{-0.6} \times 10^{-4}$ and
$0^{+1.9}_{-0} \times 10^{-5}$ with 68% confidence while avoiding decoherence
of spectator qubits due to stray resonant light that is inherent to direct
fluorescence detection.

17
The categories of this paper are: q-fin
34
The categories of this paper are: chem-ph
19
The categories of this paper are: eess
11
The categories of this paper are: hep-lat
16
The categories of this paper are: stat
1
The categories of this paper are: cs
4
The categories of this paper are: cond-mat
15
The categories of this paper are: nucl-ex
35
The categories of this paper are: mtrl-th
21
The categories of this paper are: adap-org
25
The categories of this paper are: patt-sol
6
The categories of this paper are: astro-ph
22
The categories of this paper are: chao-dyn
9
The categories of this paper are: nlin
32
The categories of this paper are: atom-ph
14
The categories of this paper are: math-ph