Charge Density Wave Instabilities and Transport Properties of the Low Dimensional Molybdenum Bronzes and Oxides

Generalized spectral signatures of electron fractionalization in quasi-one- and two-dimensional molybdenum bronzes and superconducting cuprates

“…We also introduce generalized signatures of electron fractionalization extracted from the TL model and related thinking. Presentation of these signatures provides the basic organization of the paper and we show that they are present in our ARPES spectra of several low dimensional bronzes [19], including those of quasi-1-d K 0.3 MoO 3 (the K "blue bronze") and of quasi-2-d NaMo 6 O 17 (the Na "purple bronze"). The Na purple bronze is significant here as a bridge material between 1-d and 2-d because of its "hidden 1-d" FS [20] arising from three weakly coupled 1-d chains that are mutually oriented at 120 degrees.…”

“…the inelastic scattering of photoelectrons. Charge disorder scattering giving k-loss is likely, due to the well-known tendency for alkali atom deficiencies in the purple bronzes [19], but in a FL picture it is impossible to understand the fractionalized k -loss seen here. The lack of apparent interaction between this weight and the dispersing peak, and its presence unreduced in amplitude after the peak crosses µ, shows that it cannot be simply attributed to the incoherent part of .…”

“…It is however a SC below 1.9 K [18]. For the K blue and Na purple bronzes CDW fluctuation effects above T CDW have been identified in X-ray diffraction up to room temperature [19].…”

Nonlinear transport in ${\sf \beta}$ -Na 0.33V 2O 5

“…Although there is a factor of 10 3 difference between the two threshold fields, the displayed behavior is qualitatively the same: the threshold field strongly decreases with increasing temperature. With some exceptions (for example K 0.3 MoO 3 or TaS 3 [29]) this type of behavior for in particular the first threshold field is common for many of the known charge density wave systems. At low temperature, when the number of quasiparticles is reduced, large electric fields may build up around pinning centers and the value of E * T is essentially determined by the amount of disorder in the system.…”

Evolution of coherent collective modes through consecutive charge-density-wave transitions in the(PO2)4(WO3)12

“…For (PO 2 ) 4 (WO 3 ) 2m with m = 6 in particular three CDW transitions have been observed: T CDW1 = 120 K, T CDW2 = 62 K and T CDW3 = 30 K 9,10,16 . Up to date, a substantial effort has been put into studying the electronic, magnetic and structural properties of (PO 2 ) 4 (WO 3 ) 2m bronzes, [17][18][19] however, to the best of our knowledge there is no Raman or time-resolved optical spectroscopy study of the sequence of CDW phases in (PO 2 ) 4 (WO 3 ) 2m tungsten bronzes. In this paper we therefore report on temperature and fluence dependence of the transient reflectivity in a mono-phosphate tungsten bronze (PO 2 ) 4 (WO 3 ) 2m single crystal with m = 6 (P 4 W 12 O 44 ) on a femtosecond time scale, focusing on the effect of the subsequent CDW transitions on the coherent oscillatory transient response.…”