Ferroelectric Mott-Hubbard phase in organic conductors

We present key issues of related phenomenons of the Ferroelectricity and the Charge Disproportionation in organic metals. In (TMTTF_2X the dielectric susceptibility demonstrates clear cases of the ferroelectric and anti-ferroelectric phase transitions. Both the susceptibility and the conductivity prove independence and occasional coexistence of "structurless" ferroelectric transitions and usual "anionic" ones. Their sequence gives access to physics of three types of solitons emerging upon cooling via several steps of symmetry breaking. The theory invokes a concept of the Combined Mott-Hubbard State which focuses upon weak processes of electronic Umklapp scattering coming from both the build-in nonequivalence of bonds and the spontaneous one of sites. We propose that the charge ordering in its form of the ferroelectricity exists hiddenly even in the Se subfamily (TMTSF)_2X, giving rise to the unexplained yet low frequency optical peak and the enhanced pseudogap.Comment: Proceedings of the ICSM 200

Impurity effect on low-temperature polarisation of the charge-density-waves in o-TaS3_3

The temperature dependence of the low-temperature dielectric response is studied in o-TaS$_3$ samples doped by Nb, Se, and Ni and for nominally pure ones. It is found, that the low-temperature dielectric constant depends anomalously on doping and is higher for doped crystals, whereas the temperature dependence of the characteristic time of all samples follows the activation law with nearly the same activation energy $\sim 400$ K (T>20 K). The observed behaviour is inconsistent with all available explanations of the low-temperature dielectric anomaly.Comment: RevTex, 12 pages, epsf, 2 postscript Figures. Accepted for publication in Physics Letters

The ferroelectric Mott-Hubbard phase of organic (TMTTF)2X conductors

We present experimental evidences for a ferro-electric transition in the family of quasi one- dimensional conductors (TMTTF)2X. We interpret this new transition in the frame of the combined Mott-Hubbard state taking into account the double action of the spontaneous charge disproportionation on the TMTTF molecular stacks and of the X anionic potentials

Finding new directors: The Law of supply and demand

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Torque and temperature dependence of the hysteretic voltage-induced torsional strain in tantalum trisulfide

We have measured the dependence of the hysteretic voltage-induced torsional strain (VITS) in crystals of orthorhombic tantalum trisulfide on temperature and applied torque. In particular, applying square-wave voltages above the charge-density-wave (CDW) threshold voltage, so as to abruptly switch the strain across its hysteresis loop, we have found that the time constant for the VITS to switch (at different temperatures and voltages) varied as the CDW current. Application of torque to the crystal could also change the VITS time constant, magnitude, and sign, suggesting that the VITS is a consequence of residual torsional strain in the sample which twist the CDW. Application of voltage changes the pitch of these CDW twists, which then act back on the lattice. However, it remains difficult to understand the sluggishness of the response.Comment: 20 pages, including 7 figures, to be published in PR

Сравнительный анализ технологических схем измельчения руд меди на польском предприятии KGHM POLSKA MIEDŹ S.A.

Приведено огляд технологічних схем подрібнення мідних руд на підприємтсві KGHM POLSKA MIEDŹ S.A. (Польща) та їх порівняльний аналіз.Приведен обзор технологических схем измельчения медных руд на предприятии KGHM POLSKA MIEDŹ S.A. (Польша) и их сравнительный анализ

Dielectric response of charge induced correlated state in the quasi-one-dimensional conductor (TMTTF)2PF6

Conductivity and permittivity of the quasi-one-dimensionsional organic transfer salt (TMTTF)2PF6 have been measured at low frequencies (10^3-10^7 Hz) between room temperature down to below the temperature of transition into the spin-Peierls state. We interpret the huge real part of the dielectric permittivity (up to 10^6) in the localized state as the realization in this compound of a charge ordered state of Wigner crystal type due to long range Coulomb interaction.Comment: 11 pages, 3 .eps figure

A Subtlety of the Schr\"{o}dinger Picture Dynamics

We address a mathematical and physical status of exotic (like e.g. fractal) wave packets and their quantum dynamics. To this end, we extend the formal meaning of the Schr\"{o}dinger equation beyond the domain of the Hamiltonian. The dynamical importance of the finite mean energy condition is elucidated.Comment: Minor amendments, typos corrected, to appear in Rep. Math. Phy

Ising transition in a one-dimensional quarter-filled electron system with dimerization

We examine critical properties of the quarter-filled one-dimensional Hubbard model with dimerization and with the onsite and nearest-neighbor Coulomb repulsion U and V. By utilizing the bosonization method, it is shown that the system exhibits an Ising quantum phase transition from the Mott insulating state to the charge-ordered insulating state. It is also shown that the dielectric permittivity exhibits a strong enhancement as decreasing temperature with power-law dependence at the Ising critical point.Comment: 8 pages, 1 figure, uses elsart.cls, Proc. Int. Symp. ISSP-Kashiwa 2001, submitted to J. Phys. Chem. Solid

Influence of the anion potential on the charge ordering in quasi-one dimensional charge transfer salts

We examine the various instabilities of quarter-filled strongly correlated electronic chains in the presence of a coupling to the underlying lattice. To mimic the physics of the (TMTTF)$_2$X Bechgaard-Fabre salts we also include electrostatic effects of intercalated anions. We show that small displacements of the anion can stabilize new mixed Charged Density Wave-Bond Order Wave phases in which central symmetry centers are suppressed. This finding is discussed in the context of recent experiments. We suggest that the recently observed charge ordering is due to a cooperative effect between the Coulomb interaction and the coupling of the electronic stacks to the anions. On the other hand, the Spin-Peierls instability at lower temperature requires a Peierls-like lattice coupling.Comment: Latex, 4 pages, 4 postscript figure