Ultimate Information Rate for Quantum Sensing under Multilevel Relaxation
A new theoretical analysis derives the maximum information rate achievable by a multilevel quantum sensor that is subject to excited-state relaxation back to its ground state. The result holds under unrestricted adaptive control, and the authors construct an explicit strategy that attains the bound. The model covers weak-field sensing where the field couples a ground state to multiple decaying excited states, reducing to amplitude-damping sensing.
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What this could mean
- 0–2 yearsPlausible
If the explicit adaptive strategy can be translated into implementable control sequences for existing multilevel sensors such as NV centers or trapped ions, it could guide experiments toward the ultimate precision limits set by relaxation within the next two years.
The paper provides an attainable strategy rather than only a bound, so the main remaining obstacle is mapping unrestricted adaptive control onto realistic hardware constraints such as finite pulse bandwidth, measurement back-action, and achievable qudit control. Because the underlying sensor platforms already exist, this is a near-term engineering translation rather than a requirement for new hardware.
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