A "Nonclassical Advantage in Metrology" paper

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The paper discusses a metrology experiment utilizing hypothetical closed timelike curves to enhance information gain through quantum entanglement. It proposes that a metrologist can probabilistically simulate time travel via quantum-teleportation circuits, allowing for the adjustment of input states after an interaction. This method enables the extraction of more information per probe than classical approaches permit. The experiment illustrates that entanglement can provide operational advantages that are not achievable within classical frameworks. Overall, it highlights the potential of nonclassical strategies in quantum metrology.
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Are any QM experts here at PF familiar with this research?
I have come across this paper and am wondering if QM experts here are familiar with this line of research:

https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.131.150202

The abstract reads:

We construct a metrology experiment in which the metrologist can sometimes amend the input state by simulating a closed timelike curve, a worldline that travels backward in time. The existence of closed timelike curves is hypothetical. Nevertheless, they can be simulated probabilistically by quantum-teleportation circuits. We leverage such simulations to pinpoint a counterintuitive nonclassical advantage achievable with entanglement. Our experiment echoes a common information-processing task: A metrologist must prepare probes to input into an unknown quantum interaction. The goal is to infer as much information per probe as possible. If the input is optimal, the information gained per probe can exceed any value achievable classically. The problem is that, only after the interaction does the metrologist learn which input would have been optimal. The metrologist can attempt to change the input by effectively teleporting the optimal input back in time, via entanglement manipulation. The effective time travel sometimes fails but ensures that, summed over trials, the metrologist’s winnings are positive. Our Gedankenexperiment demonstrates that entanglement can generate operational advantages forbidden in classical chronology-respecting theories.
 
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An antilinear operator ##\hat{A}## can be considered as, ##\hat{A}=\hat{L}\hat{K}##, where ##\hat{L}## is a linear operator and ##\hat{K} c=c^*## (##c## is a complex number). In the Eq. (26) of the text https://bohr.physics.berkeley.edu/classes/221/notes/timerev.pdf the equality ##(\langle \phi |\hat{A})|\psi \rangle=[ \langle \phi|(\hat{A}|\psi \rangle)]^*## is given but I think this equation is not correct within a minus sign. For example, in the Hilbert space of spin up and down, having...

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