Commensurate 4 a0-period charge density modulations throughout the Bi2Sr2CaCu2O8+x pseudogap regime

Andrej Mesaros; Kazuhiro Fujita; Stephen D Edkins; Mohammad H Hamidian; Hiroshi Eisaki; Shin-Ichi Uchida; J C Séamus Davis; Michael J Lawler; Eun-Ah Kim

doi:10.1073/pnas.1614247113

Commensurate 4 a₀-period charge density modulations throughout the Bi₂Sr₂CaCu₂O_8+x pseudogap regime

Proc Natl Acad Sci U S A. 2016 Nov 8;113(45):12661-12666. doi: 10.1073/pnas.1614247113. Epub 2016 Oct 20.

Authors

Andrej Mesaros¹, Kazuhiro Fujita², Stephen D Edkins^{1

3}, Mohammad H Hamidian^{4

5}, Hiroshi Eisaki⁶, Shin-Ichi Uchida^{6

7}, J C Séamus Davis^{8

2

3

9}, Michael J Lawler^{1

10}, Eun-Ah Kim⁸

Affiliations

¹ Laboratory of Atomic and Solid State Physics, Department of Physics, Cornell University, Ithaca, NY 14853.
² Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, NY 11973.
³ School of Physics and Astronomy, University of St. Andrews, St. Andrews, Fife KY16 9SS, Scotland.
⁴ Department of Physics, Harvard University, Cambridge, MA 02138.
⁵ Department of Physics, University of California, Davis, CA 95616.
⁶ Superconducting Electronics Group, Electronics and Photonics Research Institute, National Institute of Advanced Industrial Science and Technology, Tsukuba, Ibaraki 305-8568, Japan.
⁷ Department of Physics, University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan.
⁸ Laboratory of Atomic and Solid State Physics, Department of Physics, Cornell University, Ithaca, NY 14853; jcseamusdavis@gmail.com eun-ah.kim@cornell.edu.
⁹ Tyndall National Institute, University College Cork, Cork T12R5C, Ireland.
¹⁰ Department of Physics, Binghamton University, Binghamton, NY 13902-6000.

Abstract

Theories based upon strong real space (r-space) electron-electron interactions have long predicted that unidirectional charge density modulations (CDMs) with four-unit-cell (4a₀) periodicity should occur in the hole-doped cuprate Mott insulator (MI). Experimentally, however, increasing the hole density p is reported to cause the conventionally defined wavevector Q_A of the CDM to evolve continuously as if driven primarily by momentum-space (k-space) effects. Here we introduce phase-resolved electronic structure visualization for determination of the cuprate CDM wavevector. Remarkably, this technique reveals a virtually doping-independent locking of the local CDM wavevector at [Formula: see text] throughout the underdoped phase diagram of the canonical cuprate Bi₂Sr₂CaCu₂O₈ These observations have significant fundamental consequences because they are orthogonal to a k-space (Fermi-surface)-based picture of the cuprate CDMs but are consistent with strong-coupling r-space-based theories. Our findings imply that it is the latter that provides the intrinsic organizational principle for the cuprate CDM state.

Keywords: CuO2 pseudogap; commensurate charge density modulation; phase discommensuration.