Terahertz, Nanofabricated and Atomic Scale Probes for Density Waves Studies

Abstract: Charge and spin density waves (CDW/SDW) have been a subject of condensed matter research for decades. The current interest on this topic stems in part from the CDW/SDW status in the phase diagram of superconductors, especially high Tc and related novel superconductors. Additional long term interest in these materials and states originates in their occurrence in quasi-1D and quasi-2D geometries, making their nano- and atomic scale realizations candidates for quantum materials. In this talk, we will review several approaches we have been developing since mid 2000s, which enable better understanding of CDWs. Nanofabricated contact geometries enable discovery of some now externally controllable properties previously thought to be fundamentally material-specific [1]. Synchrotron-based experiments will be discussed as well, such as the use of X-ray nanofocusing to directly observe voltage controlled motion of electron crystal deformations [2], and the use of magneto-reflectance in THz regime [3] to elicit broad temperature range properties often hard to observe in atomic scale probes such as STM [4].
[1] Phys. Rev. B. 77, 115141.
[2] Phys. Rev. Lett. 96, 046401.
[3] A. F. Isakovic et al., in publication
[4] Phys. Rev. B. 76, 033104.