Many-body topological invariants from randomized measurements
Abstract
The classification of symmetry-protected topological (SPT) phases in one dimension has been recently achieved, and had a fundamental impact in our understanding of quantum phases in condensed matter physics. In this framework, SPT phases can be identified by many-body topological invariants, which are quantized non-local correlators for the many-body wavefunction. While SPT phases can now be realized in interacting synthethic quantum systems, the direct measurement of quantized many-body topological invariants has remained so far elusive. Here, we propose measurement protocols for many-body topological invariants for all types of protecting symmetries of one-dimensional interacting bosonic systems. Our approach relies on randomized measurements implemented with local random unitaries, and can be applied to any spin system with single-site addressability and readout. Our scheme thus provides a versatile toolbox to experimentally classify interacting SPT phases.
Keywords
Cite
@article{arxiv.1906.05011,
title = {Many-body topological invariants from randomized measurements},
author = {Andreas Elben and Jinlong Yu and Guanyu Zhu and Mohammad Hafezi and Frank Pollmann and Peter Zoller and Benoît Vermersch},
journal= {arXiv preprint arXiv:1906.05011},
year = {2020}
}