Helper-assisted quantum sensing with low dressed-state leakage
Abstract
We study a two-qubit sensing protocol in which only a helper qubit is read out. Calibrated loading and unloading encode a transverse signal in the helper's phase, keep leakage out of a selected dressed-state band small, and return the sensor close to its idle ground state. We derive an information bound for a single sensor whose excitation stays below a prescribed budget, and simulate repeated operation with an uncertain coupling and finite-duration resets in a driven open-system model. At the tested settings, finite measurement records support estimation with infrequent resets. A helper flip at zero coupling, combined with a reversal of the coupling sign, suppresses a static helper offset shared across a record while retaining the signal, at a cost of about 27% of the no-offset information of a plain sequence of equal duration. Under slowly varying noise, averaging each cycle's likelihood over the correct noise law removes most of the added bias, and a wrong noise law can worsen the estimate. A selected directly read sensor with ideal controls and repeated nondemolition verification has the higher information rate. Any practical benefit of avoiding direct readout therefore requires a device-specific disturbance model.
Related
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- Quantum-Nondemolition Probing of Multiphoton Transitions between Dressed States in a Strongly Driven Jaynes--Cummings System
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- Quantum Secret Sharing with a Helper and Programmable Access Structures
- Codes for Quantum Secret Sharing with a Helper
BibTeX
@misc{abdullah2026helperassisted,
title = {{Helper-assisted quantum sensing with low dressed-state leakage}},
author = {Shirwan Abdullah},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2610.41404},
eprint = {2610.41404},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2610.41404},
}
RIS
TY - UNPB
TI - Helper-assisted quantum sensing with low dressed-state leakage
AU - Shirwan Abdullah
PY - 2026
DA - 2026/10/30
PB - arXiv
DO - 10.48550/arxiv.2610.41404
UR - https://arxiv.org/abs/2610.41404
AB - We study a two-qubit sensing protocol in which only a helper qubit is read out. Calibrated loading and unloading encode a transverse signal in the helper's phase, keep leakage out of a selected dressed-state band small, and return the sensor close to its idle ground state. We derive an information bound for a single sensor whose excitation stays below a prescribed budget, and simulate repeated operation with an uncertain coupling and finite-duration resets in a driven open-system model. At the tested settings, finite measurement records support estimation with infrequent resets. A helper flip at zero coupling, combined with a reversal of the coupling sign, suppresses a static helper offset shared across a record while retaining the signal, at a cost of about 27% of the no-offset information of a plain sequence of equal duration. Under slowly varying noise, averaging each cycle's likelihood over the correct noise law removes most of the added bias, and a wrong noise law can worsen the estimate. A selected directly read sensor with ideal controls and repeated nondemolition verification has the higher information rate. Any practical benefit of avoiding direct readout therefore requires a device-specific disturbance model.
ER -