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Title: Universality of the charge-sharpening transition in U(1) monitored circuits
Plain: When circuits conserve a quantity like total charge, a second transition appears: below it, an observer cannot quickly learn the total charge from the measurements. Which universal class this learning transition belongs to is not settled.
Precise: In $1+1\mathrm{D}$ monitored circuits conserving $U(1)$ charge, a charge-sharpening transition at $p_{\#} < p_{c}$ separates phases where the total charge can or cannot be inferred from the measurement record in time $\operatorname{O}(L)$. Determine its universality class; a Kosterlitz-Thouless-type field theory was proposed (Barratt et al. 2022).
Settled by: Large-scale numerics of finite-q circuits matched to field-theory predictions for the scaling of charge variance and learning time.
Kind: well-posed
Answer type: classification
References: (empty)
Literature status: open
Status note: (empty)
Posed since: 2022