2010/11/24 by Yi Zhou, Patrick A Lee · 1 citation
Physics and Astronomy · #cond-mat.str-el
paper · pdf · doi:10.1103/physrevlett.106.056402
published as Phys. Rev. Lett. 106, 056402 (2011) · 4+epsilon pages of main text + 12 pages of supplementary material
arxiv created 2010/11/24 · arxiv updated 2011/02/09
Several experimental candidates for quantum spin liquids have been discovered in the past few years which appear to support gapless fermionic S = 1\over 2 excitations called spinons. The spinons may form a Fermi sea coupled to a U(1) gauge field, and may undergo a pairing instability. We show that despite being charge neutral, the spinons couple to phonons in exactly the same way that electrons do in the long wavelength limit. Therefore we can use sound attenuation to measure the spinon mass and lifetime. Furthermore, transverse ultrasonic attenuation is a direct probe of the onset of pairing because the Meissner effect of the gauge field causes a "rapid fall" of the attenuation at Tc in addition to the reduction due to the opening of the energy gap. This phenomenon, well known in clean superconductors, may reveal the existence of the U(1) gauge field.