Many-body invariants from statistical correlations of randomized measurements

Abstract: With the advances of quantum simulators in implementing various quantum many-body states, it is important to find efficient ways to characterize and measure many-body states, without resorting to full quantum state tomography. Specifically, in contrast to electronic materials, where the measurements are mainly within the linear-response paradigm, quantum simulators offer unique access to the full wave function that inspires novel probing approaches. In this talk, I discuss how various quantities, such as entanglement spectrum, symmetry-protected topological invariants, and fractional many-body Chern number could be extracted. In the latter case, we show how such an invariant can be measured, using a single wave function, without the knowledge of the Hamiltonian. This should be contrasted to the conventional way, where on requires a family of many-body wave functions parameterized by twist angles in order to calculate the Berry curvature.

Science Advance 6, 3666 (2020) arxiv 2005.13543 arxiv 2005.13677

quantum gasesquantum computing and informationgeneral relativity and quantum cosmologyquantum physics

Audience: researchers in the topic

Q-FARM Seminar Series