Publications [#302509] of Sara Haravifard

Papers Published
  1. Feng, Y; Wang, J; Jaramillo, R; van Wezel, J; Haravifard, S; Srajer, G; Liu, Y; Xu, Z-A; Littlewood, PB; Rosenbaum, TF, Order parameter fluctuations at a buried quantum critical point., Proceedings of the National Academy of Sciences of the United States of America, vol. 109 no. 19 (May, 2012), pp. 7224-7229 [doi] .

    Quantum criticality is a central concept in condensed matter physics, but the direct observation of quantum critical fluctuations has remained elusive. Here we present an X-ray diffraction study of the charge density wave (CDW) in 2H-NbSe(2) at high pressure and low temperature, where we observe a broad regime of order parameter fluctuations that are controlled by proximity to a quantum critical point. X-rays can track the CDW despite the fact that the quantum critical regime is shrouded inside a superconducting phase; and in contrast to transport probes, allow direct measurement of the critical fluctuations of the charge order. Concurrent measurements of the crystal lattice point to a critical transition that is continuous in nature. Our results confirm the long-standing expectations of enhanced quantum fluctuations in low-dimensional systems, and may help to constrain theories of the quantum critical Fermi surface.