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This content will become publicly available on November 1, 2017

Title: Multiple charge density wave states at the surface of TbTe3

We studied TbTe3 using scanning tunneling microscopy (STM) in the temperature range of 298–355 K. Our measurements detect a unidirectional charge density wave (CDW) state in the surface Te layer with a wave vector consistent with that of the bulk qCDW = 0.30 ± 0.01c*. However, unlike previous STM measurements, and differing from measurements probing the bulk, we detect two perpendicular orientations for the unidirectional CDW with no directional preference for the in-plane crystal axes (a or c axis) and no noticeable difference in wave vector magnitude. In addition, we find regions in which the bidirectional CDW states coexist. We propose that observation of two unidirectional CDW states indicates a decoupling of the surface Te layer from the rare-earth block layer below, and that strain variations in the Te surface layer drive the local CDW direction to the specific unidirectional or, in rare occurrences, bidirectional CDW orders observed. This indicates that similar driving mechanisms for CDW formation in the bulk, where anisotropic lattice strain energy is important, are at play at the surface. Furthermore, the wave vectors for the bidirectional order we observe differ from those theoretically predicted for checkerboard order competing with stripe order in a Fermi-surface nesting scenario,more » suggesting that factors beyond Fermi-surface nesting drive CDW order in TbTe3. As a result, our temperature-dependent measurements provide evidence for localized CDW formation above the bulk transition temperature TCDW.« less
Authors:
 [1] ;  [1] ;  [1] ;  [1] ;  [2] ;  [2] ;  [1]
  1. Clark Univ., Worcester, MA (United States)
  2. Stanford Univ., Stanford, CA (United States); SLAC National Accelerator Lab., Menlo Park, CA (United States)
Publication Date:
Grant/Contract Number:
AC02-76SF00515
Type:
Accepted Manuscript
Journal Name:
Physical Review B
Additional Journal Information:
Journal Volume: 94; Journal Issue: 20; Journal ID: ISSN 2469-9950
Publisher:
American Physical Society (APS)
Research Org:
SLAC National Accelerator Lab., Menlo Park, CA (United States)
Sponsoring Org:
USDOE
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY
OSTI Identifier:
1348986
Alternate Identifier(s):
OSTI ID: 1330600