Unverified 2026

Sliding-Friction Recurrent Memory

Implementation & benchmark of arXiv:2607.14383 — Long-lived memory in sliding spin chains

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Source paper: Long-lived memory in sliding spin chains arXiv:2607.14383 ⓘ · analyzed Aug 30, 2026

AI-generated research hypothesis, automatically tested. Not peer-reviewed.

Idea description

Replace a single recurrent state with two coupled one-dimensional latent chains whose relative alignment is periodically shifted during inference. Ferromagnetic coupling preserves locally coherent patterns, while controlled sliding produces a nonequilibrium friction effect that can make global magnetization substantially longer-lived than in a static noisy chain. The shift velocity acts as a measurable memory-control parameter rather than an unconstrained architectural hyperparameter.

Formulas

$$\tau(0)=\exp\!\big(O(\beta J)\big),\qquad \tau(v>v_c)=\exp\!\big(O((\beta J)^2v\ln v)\big).$$
$$E(t)=-J\sum_{c\in\{a,b\}}\sum_{i=1}^{N-1}s_i^{(c)}s_{i+1}^{(c)}-K\sum_{i=1}^{N}s_i^{(a)}s_{i+q(t)}^{(b)},\qquad q(t+1)=q(t)+v.$$
$$P(s_i^{(c)}\mapsto-s_i^{(c)})=\frac{1}{1+\exp(\beta\Delta E_i^{(c)})},\qquad \Delta E_i^{(c)}=E(s_i^{(c)}\mapsto-s_i^{(c)})-E(s_i^{(c)}).$$
$$\tau_\theta=\inf\{t\ge 0:\ |m(t)|\le\theta|m(0)|\},\qquad \widehat{\tau}_\theta(v)=\operatorname{median}_{r=1:R}\tau_{\theta,r}(v).$$

Mathematical statement

Let s_i^(a),s_i^(b) in {-1,+1} denote latent spins at site i in chains a and b, J>0 be the ferromagnetic coupling, and beta be inverse noise temperature. The paper predicts an equilibrium memory time tau(0)=exp(O(beta J)) and, for sliding speed v above a small crossover v_c, tau(v)=exp(O((beta J)^2 v ln v)); empirical fits should determine prefactors and verify the logarithmic scaling. In the neural adaptation, define E_a=-J sum_i s_i^(a)s_(i+1)^(a), E_b=-J sum_i s_i^(b)s_(i+1)^(b), and inter-chain energy E_ab=-K sum_i s_i^(a)s_(i+q(t))^(b), where K>0 is cross-chain coupling and q(t) is relative shift. A stochastic update uses Glauber probability P(s_i maps to -s_i)=[1+exp(beta Delta E_i)]^{-1}, where Delta E_i is the energy increase from the flip. Set q(t+1)-q(t)=v. The readout is coarse magnetization m(t)=N^{-1} sum_i (s_i^(a)+s_i^(b))/2. The transferable mechanism is a change in lifetime scaling near v_c.

Implementation notes

Integrate the mechanism as a recurrent state module before the task-specific readout. Maintain two tensors S_a and S_b with shape batch by chain-length by latent-width, initialize them from the input embedding, and use tanh states for differentiable training or straight-through binary states for a direct spin implementation. At each recurrent step, compute nearest-neighbor ferromagnetic messages J times the sum of the left and right neighboring states; shift or interpolate S_b by the current offset q; add cross-chain messages K times the shifted state; inject temperature-scaled Gaussian or logistic noise; update each chain with S_new=tanh(S+alpha times message); and advance q by v. Use a small learned readout from pooled magnetization and local features. The paper supplies the lifetime-scaling mechanism, while the neural implementation must estimate J, K, beta, v_c, and asymptotic prefactors empirically. First test a delayed binary-memory task storing a random bit for horizons from 1 to 10,000. Compare a single noisy recurrent chain, two static coupled chains with v=0, and the sliding model over a logarithmic grid of v. Measure median threshold lifetime tau_hat_0.2 and fit log lifetime versus beta J at v=0 and versus (beta J)^2 v log(v) above crossover. The falsifiable prediction is a kink or slope change at a reproducible small v_c, with the sliding model exceeding the static-chain lifetime in the high-beta J regime. If there is no crossover or lifetime gain, reject the mechanism.

Verification

This idea has not been verified yet.

Verification happens in two stages: Stage 1 — a mechanism check on a toy system confirms the claimed mathematical phenomenon reproduces; Stage 2 — a benchmark implements the idea on a real (small) neural network task and compares it against a tuned baseline over 8 paired seeds with a permutation test.

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