International Workshop on Electronic Crystals
S. Brazovskii, P. Monceau and N. Kirova
J. Phys. IV France 131 (2005) 197-202
DOI: 10.1051/jp4:2005131049

Interlayer tunneling spectroscopy of layered CDW materials

Yu.I. Latyshev¹, P. Monceau², S.A. Brazovski³, A.P. Orlov¹, A.A. Sinchenko⁴, Th. Fournier² and E. Mossang<sup>5

1</sup>  Institute of Radioengineering and Electronics, Russian Ac. Sci., 125009 Moscow, Russia
²  CRTBT-CNRS, Grenoble, BP. 166, 38042 Grenoble, France
³  LPTMS-CNRS, Bât. 100, Universite Paris-Sud, 91405 Orsay, France
⁴  Moscow Engineering-Physics Institute, 115409 Moscow, Russia
⁵  LCMI-CNRS, Grenoble, BP. 166, 38042 Grenoble, France

Abstract
We have measured intrinsic tunneling spectra of charge density wave (CDW) materials NbSe₃ and o-TaS₃ in sub-micron scale mesa structures. Beyond the interband tunneling across the CDW gap, , we observe intragap states at the voltage which we associate with creation of the amplitude soliton. The onset of the tunneling occurs only above a threshold voltage followed by a quasi-periodic staircase spectrum. We interpret that behavior as the CDW phase decoupling between neighboring layers via the formation of a grid of dislocation lines. In NbSe₃, the application of a high magnetic field (up to 27 T) yields a strong suppression of the tunneling density of states within the CDW gap indicating a possible field induced metal-insulator transition.

© EDP Sciences 2005