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arXiv · 2408.13096

Efficient post-selection in light-cone correlations of monitored quantum circuits

Jimin Li·Robert L. Jack·Bruno Bertini·Juan P. Garrahan
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Abstract

We consider how to target evolution conditioned on atypical measurement outcomes in monitored quantum circuits, i.e., the post-selection problem. We show that for a simple class of measurement schemes, post-selected light-cone dynamical correlation functions can be obtained efficiently from the averaged correlations of a different unitary circuit. This connects rare measurement outcomes in one circuit to typical outcomes in another one. We derive conditions for the existence of this rare-to-typical mapping in brickwork quantum circuits made of XYZ gates. We illustrate these general results with a model system that exhibits a dynamical crossover (a smoothed dynamical transition) in event statistics, and discuss extensions to more general dynamical correlations.

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Jimin Li, Robert L. Jack, Bruno Bertini, Juan P. Garrahan. 2024-08-23. Efficient post-selection in light-cone correlations of monitored quantum circuits. https://doi.org/10.1103/physrevb.111.024309

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