A universal loss-limited optimum for fixed multi-pass quantum sensing per absorbed photon
A new arXiv preprint analyzes fixed multi-pass quantum sensing schemes in which a single photon traverses a sample repeatedly. It treats the sample, not the light, as the scarce resource, using information gained per absorbed photon as the figure of merit. The authors derive a loss-limited optimum for all such fixed schemes, governed by a single constant.
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What this could mean
- 0–2 yearsPlausible
This could give experimental groups a ready-made benchmark for tuning pass count and input state in loss-limited multi-pass measurements, without solving a fresh optimization for each setup.
If the universal constant can be computed from measurable loss or transmission parameters, a lab could compare its measured information per absorbed photon against the bound and adjust the number of passes accordingly. The result is theoretical, so near-term use depends on casting the bound in measurable quantities, but that is a natural and near-term step.
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