2010/02/25 by Christophe Brun, Zhao-Zhong Wang, P. Monceau +3
Engineering · Materials Science · Physics and Astronomy · #Charge (physics) #Charge density wave #Condensed matter physics #Geometry #Molecular Junctions and Nanostructures #Order (exchange) #Organic and Molecular Conductors Research #Phase transition #Phonon #Physics #Physics of Superconductivity and Magnetism #Quantum mechanics #Scanning tunneling microscope #Superconductivity #Surface (topology) #Transition temperature #cond-mat.mes-hall
paper · pdf · doi:10.1103/physrevlett.104.256403
published as Phys. Rev. Lett. 104, 256403 (2010) · 5 pages, 2 figures
arxiv created 2010/02/25 · openalex publication_date 2010/06/24 · arxiv updated 2010/07/29 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
The two charge-density wave (CDW) transitions in NbSe3 were investigated by scanning tunneling microscopy (STM) on an in situ cleaved (b, c) plane. The temperature dependence of first-order CDW satellite spots, obtained from the Fourier transform of the STM images, was measured between 5 and 140 K to extract the surface critical temperatures (Ts). The low-T CDW transition occurs at T2s=70-75 K, more than 15 K above the bulk T2b=59 K while at exactly the same wave number. A plausible mechanism for such an unusually high surface enhancement is a softening of transverse phonon modes involved in the CDW formation. The regime of 2D fluctuations is analyzed according to a Berezinskii-Kosterlitz-Thouless type of surface transition, expected for this incommensurate 2D CDW, by extracting the temperature dependence of the order parameter correlation functions.