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PIRSA:17050081

Z_2 topological order near the Neel state of the square lattice antiferromagnet

APA

Sachdev, S. (2017). Z_2 topological order near the Neel state of the square lattice antiferromagnet. Perimeter Institute. https://pirsa.org/17050081

Subir Sachdev

Harvard University

Talk number
PIRSA:17050081
Collection
Abstract

We classify quantum states proximate to the semiclassical Neel state of the spin S=1/2 square lattice antiferromagnet with two-spin near-neighbor and four-spin ring exchange interactions. Motivated by a number of recent experiments on the cuprates and the iridates, we examine states with Z_2 topological order, an order which is not present in the semiclassical limit. Some of the states break one or more of reflection, time-reversal, and lattice rotation symmetries, and can account for the observations. We discuss implications for the pseudogap phase.