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arXiv · 1906.05011

Many-body topological invariants from randomized measurements

Andreas Elben·Jinlong Yu·Guanyu Zhu·Mohammad Hafezi·Frank Pollmann·Peter Zoller·Benoît Vermersch
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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.

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Andreas Elben, Jinlong Yu, Guanyu Zhu, Mohammad Hafezi, Frank Pollmann, Peter Zoller, Benoît Vermersch. 2019-06-12. Many-body topological invariants from randomized measurements. https://doi.org/10.1126/sciadv.aaz3666

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