Order parameter fluctuations at a buried quantum critical point.
Published
Journal Article
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.
Full Text
Duke Authors
Cited Authors
- Feng, Y; Wang, J; Jaramillo, R; van Wezel, J; Haravifard, S; Srajer, G; Liu, Y; Xu, Z-A; Littlewood, PB; Rosenbaum, TF
Published Date
- May 2012
Published In
Volume / Issue
- 109 / 19
Start / End Page
- 7224 - 7229
PubMed ID
- 22529348
Pubmed Central ID
- 22529348
Electronic International Standard Serial Number (EISSN)
- 1091-6490
International Standard Serial Number (ISSN)
- 0027-8424
Digital Object Identifier (DOI)
- 10.1073/pnas.1202434109
Language
- eng