共查询到20条相似文献,搜索用时 15 毫秒
1.
J.J. Hopfield 《Solid State Communications》1974,14(8):727-729
The ‘effective field’ model of the Peierls transition in one-dimensional metals is shown to have a dynamic instability in the presence of a large electric field. The behavior is analogous to laser action, and has a critical temperature above that of the static instability. 相似文献
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We show that an applied magnetic field will suppress the Peierls instability in one-dimensional conductors. The effect is big enough to be observable. In sufficiently strong fields the transition between the metallic and insulating state is due to the condensation of a phonon with wave vectorq≠2p F, but close to 2p F. The role of spinorbit interactions is also discussed. 相似文献
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The Peierls instability is studied for a one-dimensional tight-binding model of conduction electrons in the half-filled case. The long range Coulomb interaction as well as the electron-phonon coupling are taken into account. It is found that the Peierls distortion is hindered by the long wavelength charge fluctuations due to the Coulomb interaction. 相似文献
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Behaviour of the quasi-one-dimensional Peierls insulator (PI) with a doubled lattice period (of the trans-polyacetylene type) is studied in the uniform electric field The electric field polarizes the insulator thus decreasing the gap Δ in the quasiparticle spectrum and creates by tunnelling charge carriers pairs. Depending on the field strength direct creation of soliton-antisoliton pairs or electron-hole pairs (e-h) takes place. The (e-h) pairs deform the lattice forming polarons. For the cis-type polyacetylene the superinsulator phase with soliton confinement exists. The latter is characterized by a great number of soliton-antisoliton quantum levels. Because of the charges generation the process of insulator-to-metal transition becomes continuous. 相似文献
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We study the superconducting transition temperature (Tc) and the Peierls instability temperature (Tp) using Eliashberg type equations for both Tc and Tp self consistently with finite interchain coupling. We show that Tc > Tp below a critical electron-phonon coupling constant which depends on the bare phonon frequency. This determines an upper bound on Tc so that for higher transition temperatures Tp > Tc and superconductivity is unlikely. Higher values of Tc are possible if the interchain coupling is increased above a critical value where the Peierls instability is suppressed. 相似文献
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We suggest that a magnetic-field-induced Peierls
instability accounts for the recent experiment of Zhang et
al. in which unexpected quantum Hall plateaus were observed at high
magnetic fields in graphene on a substrate. This Peierls instability
leads to an out-of-plane lattice distortion resulting in a charge
density wave (CDW) on sublattices A and B of the graphene honeycomb
lattice. We also discuss alternative microscopic scenarios proposed
in the literature and leading to a similar CDW ground state in
graphene. 相似文献
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Mean field calculations of the Peierls instability have been carried out for arbitrary bandfilling both in the case of free electrons as well as for the tightbinding approximation. New expressions for Δ(0) and Tp are derived which change the experimentally derived λ to a more reasonable value. Δ(0)/kBTp may differ significantly from the BCS value 1.76 in the tightbinding approximation. 相似文献
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C.S. Koonce 《Solid State Communications》1974,14(11):1141-1144
Peierls transitions in one dimensional charge transfer salts in which both donor and acceptor molecules have even valency such as TTF-TCNQ have been studied. Transitions involving macroscopic occupation of phonon states of wavevector and |kF(TTF) ? kF (TCNQ)| can occur as well as transitions of wavevector 2kF(TTF) [and 2kF(TCNQ)]. 相似文献
10.
A. L. Semenov 《Physics of the Solid State》1998,40(11):1915-1920
A microscopic theory of the appearance of electron-phonon instability and a semiconductor-metal phase transition away from
thermodynamic equilibrium in a Peierls system upon the optical excitation of electron-hole pairs is devised. An equation which
specifies the dependence of the order parameter of the phase transition and the uniquely related gap width in the electron
spectrum, on the concentration n of conduction-band electrons is obtained. The critical concentration n=n
c, above which the semiconductor phase of the system is unstable toward the transition to the metallic state, is calculated.
A comparison with an experiment on the irradiation of a substrate-supported vanadium dioxide film by a laser pulse is made.
Fiz. Tverd. Tela (St. Petersburg) 40, 2113–2118 (November 1998) 相似文献
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Blumenstein C Schäfer J Morresi M Mietke S Matzdorf R Claessen R 《Physical review letters》2011,107(16):165702
The one-dimensional (1D) model system Au/Ge(001), consisting of linear chains of single atoms on a surface, is scrutinized for lattice instabilities predicted in the Peierls paradigm. By scanning tunneling microscopy and electron diffraction we reveal a second-order phase transition at 585 K. It leads to charge ordering with transversal and vertical displacements and complex interchain correlations. However, the structural phase transition is not accompanied by the electronic signatures of a charge density wave, thus precluding a Peierls instability as origin. Instead, this symmetry-breaking transition exhibits three-dimensional critical behavior. This reflects a dichotomy between the decoupled 1D electron system and the structural elements that interact via the substrate. Such substrate-mediated coupling between the wires thus appears to have been underestimated also in related chain systems. 相似文献
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Das KK 《Physical review letters》2003,90(17):170403
We analyze the phase stability and the response of a mixture of bosons and spin-polarized fermions in one dimension (1D). Unlike in 3D, phase separation happens for low fermion densities. The dynamics of the mixture at low energy is independent of the spin-statistics of the components, and the modes are essentially undamped. 相似文献
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M.Ya. Azbel 《Solid State Communications》1981,37(10):789-790
Singular extended states among random system localized states are proved to be a general rule. When a Fermi energy coincides with the extended state energy, a residual resistance becomes proportional to the square of the system length. 相似文献
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We derive exact relations that connect the universal C/k4-decay of the momentum distribution at large k with both thermodynamic properties and correlation functions of two-component Fermi gases in one dimension with contact interactions. The relations are analogous to those obtained by Tan in the three-dimensional case and are derived from an operator product expansion of the one- and two-particle density matrix. They extend earlier results by Olshanii and Dunjko (2003) [24] for the bosonic Lieb–Liniger gas. As an application, we calculate the pair distribution function at short distances and the dimensionless contact in the limit of infinite repulsion. The ground state energy approaches a universal constant in this limit, a behavior that also holds in the three-dimensional case. In both one and three dimensions, a Stoner instability to a saturated ferromagnet for repulsive fermions with zero range interactions is ruled out at any finite coupling. 相似文献
18.
Stewart D. Johnson 《Communications in Mathematical Physics》1989,122(2):293-320
Families of unimodal maps satisfying
- T λ: [?1,1]?[?1,1] withT(±1)=?1 and |T λ ′ (1)|>1.
- T λ(x) isC 2 inx 2 and λ, and symmetric inx.
- T 0(0)=0,T 1(0)=1 with \(\frac{d}{{d\lambda }}\) T λ(0)>0
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