Finite-size Entanglement Certification via Third-Order Local Randomized Measurements
Giovanni Scala, Corrado Cosimo Mattiacci, Dorota Pietryka +1 more
Certifying entanglement in high-dimensional systems usually requires full state tomography, whose cost grows rapidly with the system dimension. Local randomized measurements offer a scalable alternative, but existing tests based on second-order correlations access only limited information about the state. Here, we derive a finite-size entanglement certificate that extends local randomized measurements to third order. The additional third-order information reveals entanglement that remains undetected at second order, while a dimension-independent concentration bound provides rigorous control of finite-sample errors. Our result opens a practical route to extracting stronger entanglement information from experimental platforms without the dimension-dependent overhead of state tomography.
quant-pharXiv:2609.08635•Sep 9, 2026•0 citations