2023/12/07 by Brenden Roberts, Roberts, Brenden, Sagar Vijay +3
Chemistry · Computer Science · #FOS: Physical sciences #Molecular spectroscopy and chirality #Quantum Computing Algorithms and Architecture #Quantum Information and Cryptography #Quantum Physics (quant-ph) #Strongly Correlated Electrons (cond-mat.str-el)
paper · pdf · doi:10.48550/arxiv.2312.04500
openalex publication_date 2023/12/07 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/01
The Pancharatnam phase is a generalization of the Berry phase that applies to discrete sequences of quantum states. Here, we show that the Pancharatnam phase is a natural invariant for a wide class of quantum many-body dynamics involving measurements. We specifically investigate how a non-trivial Pancharatnam phase arises in the trajectories of Floquet quantum error-correcting codes and show that this phase can be extracted in a "computationally-assisted" interferometry protocol, involving additional post-processing based on the measurement record that defines a given quantum many-body trajectory. This Pancharatnam phase can also be directly related to the Berry phase accrued by continuous unitary evolution within a gapped phase. For the \mathbb Z2 Floquet code of Hastings and Haah, we show that the associated family of unitary evolutions is the radical chiral Floquet phase. We demonstrate this correspondence explicitly by studying an exactly-solvable model of interacting spins.