Readout-induced decay of records
Readout-induced decay of records
Purpose
Test whether a persistent distinction qualifies as a record only when it can be accessed repeatedly without significantly accelerating decay.
Links to claims
- Records require readable persistence
- Persistent distinction equals suppressed transition rate (optional)
System
A bistable memory element (two metastable basins) subject to noise, with an adjustable readout coupling that extracts state information.
Setup
- Memory variable: x(t) (effective state coordinate)
- Basins: A and B (partition defined by x < 0 vs x > 0, or by attractor membership)
- Noise model: thermal or stochastic forcing with known intensity D
- Readout channel: a probe that couples to x(t) with strength g and is applied at rate f (reads per unit time)
Distinction definition
- Effective state variables: x(t)
- Partition rule: A if x(t) < 0, B if x(t) > 0 (or basin membership)
- Persistence baseline: measure lifetime τ0 with g = 0
Readout implementation (conceptual)
During readout events, the probe interacts with the memory element. That interaction should have two effects:
- It reveals state (increases measurement signal-to-noise).
- It perturbs the dynamics (adds back-action noise or reduces barrier height).
Measurement / metric
Primary:
- τ(g, f): mean dwell time in a basin (or mean first-passage time across the boundary)
- k(g, f) = 1 / τ(g, f): transition rate
Secondary:
- Readout fidelity: P(correct state | probe output)
- Back-action proxy: additional effective diffusion ΔD(g) or effective barrier reduction ΔU(g)
Experimental protocol
- Calibrate baseline: measure τ0 at g = 0 across noise levels D.
- Turn on readout with fixed f; sweep g; measure τ(g, f) and fidelity.
- Fix g; sweep f; measure τ(g, f).
- Repeat across at least two barrier heights (or constraint strengths).
Expected outcomes
If claim holds:
- τ(g, f) decreases as g increases and as f increases (readout accelerates decay).
- There exists a regime where fidelity is high yet τ is not strongly reduced (a “usable record regime”).
If claim fails:
- τ is insensitive to g and f, or decay is dominated entirely by baseline noise regardless of probing.
Notes
This tests an operational distinction between:
- a persistent distinction (stable state),
- and a record (stable state that remains stable under repeated access).