Charge density wave transport in a novel inorganic chain compound, (TaSe4)2I

Electronic Instability in a Zero-Gap Semiconductor: The Charge-Density Wave in(TaSe4)2I

“…Finally, the proposed scenario naturally explains the puzzling semiconductor-to-semiconductor transition observed in transport at T CDW [13,19]. For T > T CDW , the activated behaviour (∆ HT ≈ 0.2 eV) reflects the diffusive motion of small polarons, which reduces the conductivity by a factor e −Ep/kBT [33].…”

“…At T CDW = 263 K it undergoes a charge density wave (CDW) transition, accompanied by an incommensurate structural distorsion [10,11]. As expected, the instability affects the electronic structure, and clear signatures of the transition are found in the electrical resistivity [12,13], the magnetic susceptibility [14] and the optical response [15]. The CDW phase is rather unusual.…”

Chaotic ac Conductivity in the Charge-Density-Wave State of(TaSe4)2I

“…, the low-field ac conductivity o-(co) is strongly frequency dependent with anomalous response observed in the megahertz to gigahertz region. 5,7 The excess dc and ac responses have been interpreted as due to collective motion of the CDW condensate. For low applied dc fields the CDW is assumed to be pinned to the underlying lattice by impurities, and only when the field energy exceeds the pinning potential does the CDW become mobile and contribute to the dc conductivity by the Frolich 8 mechanism.…”

Solitons in One-Dimensional Systems

“…Furthermore independenee of the CDW amplitude on the eleetric eurrent as seen by X-ray even in the nonlinear regime [206] strengthens the idea that motion of the CDW eondensate plays a erucial role in the nonlinear transport. More reeently new systems like TaS3 (orthorhombic and monoclinic) [207,208] , (TaSe4)2 I, (NbSe4)10/31 [209,210] and the blue bronze K O•3Mo0 3 and Rb o.3Mo03 [211] are found to exhibit similar anomalous transport. Therefore the anomalous transport observed in the CDW states of NbSe3 is generie in a class of quasi-one dimensional eompounds.…”