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Probing Anomalous Longitudinal Fluctuations of the Interacting Bose Gas via Bose-Einstein Condensation of Magnons

Andreas Kreisel·Nils Hasselmann·Peter Kopietz
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Abstract

The emergence of a finite staggered magnetization in quantum Heisenberg antiferromagnets subject to a uniform magnetic field can be viewed as Bose-Einstein condensation of magnons. Using non-perturbative results for the infrared behavior of the interacting Bose gas, we present exact results for the staggered spin-spin correlation functions of quantum antiferromagnets in a magnetic field at zero temperature. In particular, we show that in dimensions 1 < D <= 3 the longitudinal dynamic structure factor S_parallel(q,omega) describing staggered spin fluctuations in the direction of the staggered magnetization exhibits a critical continuum whose weight can be controlled experimentally by varying the magnetic field.

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Andreas Kreisel, Nils Hasselmann, Peter Kopietz. 2007-01-09. Probing Anomalous Longitudinal Fluctuations of the Interacting Bose Gas via Bose-Einstein Condensation of Magnons. https://doi.org/10.1103/physrevlett.98.067203

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