Theory of pinning of a spin-density wave by nonmagnetic impurities

Tüttő, I.; Zawadowski, A.

doi:10.1103/physrevlett.60.1442

Cited by 42 publications

(19 citation statements)

References 16 publications

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“…The excitations in the absence of impurities are pairs of ±2π solitons and antisolitons, the phase of which winds by ±2π within a correlation length ξ = v F /2πw. A SDW is viewed as the superposition of two out-of-phase CDWs for spin-up and spin-down electrons, and the SDW pinning energy is obtained to second order as [14,15,16,17] …”

mentioning

confidence: 99%

Interplay between Phase Defects and Spin Polarization in the Specific Heat of the Spin-Density-Wave Compound(TMTTF)2Brin a Magnetic Field

Mélin¹,

Lasjaunias²,

Sahling

et al. 2006

Phys. Rev. Lett.

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Equilibrium heat relaxation experiments provide evidence that the ground state of the commensurate spin density wave (SDW) compound (TMTTF)2Br after the application of a sufficient magnetic field is different from the conventional ground state. The experiments are interpreted on the basis of the local model of strong pinning as the deconfinement of soliton-antisoliton pairs triggered by the Zeeman coupling to spin degrees of freedom, resulting in a magnetic field induced density wave glass for the spin carrying phase configuration.PACS numbers: 75.30.Fv,75.40.Cx,75.10.Nr Metastability results from energy minima in a system phase space, separated from each other by energy barriers. In some complex systems such as spin glasses, the number of metastable states and the scaling of the energy barriers with the system size are such that ergodicity is broken, meaning that time averaging is not equivalent to ensemble averaging because the system is "trapped" in a valley of the energy landscape. Metastability is also found in model systems such as molecular magnets or Josephson junctions, described by an energy potential V (ϕ) as a function of a single degree of freedom ϕ. We investigate below experimentally and theoretically the residual degrees of freedom of a spin density wave (SDW) at very low temperature in a magnetic field, interpreted as the properties of a classical potential V (ϕ(y i )) for the SDW phase ϕ(y i ) at the coordinate y i along the chain of a strong pinning impurity.Below the Peierls transition temperature, charge density waves (CDWs) and SDWs in quasi-one-dimensional (quasi-1D) compounds are characterized by a spatial modulation of the electronic density (or spin) along the chains. The phase profile is the result of a compromise between the elastic energy that penalizes large phase gradients, and the pinning energy that tends to fix the phase at the strong pinning centers. These two ingredients of the Fukuyama-Lee-Rice model [1] lead to metastability as the result of collective pinning. Collective pinning is however frozen below a glass transition of order ∼ 50 K, as shown by dielectric susceptibility experiments [2]. At very low temperature, the residual degrees of freedom in a zero magnetic field correspond to the local defects of the local model of strong pinning [3,4,5,6,7,8]. Larkin [4] and Ovchinnikov [5] have shown that a single strong pinning impurity leads to a bound state of an electronlike soliton and a hole-like antisoliton. This results in a potential V (ϕ(y i )) with multiple minima [6], leading to slow relaxation in agreement with the very low temperature heat relaxation experiments [5].In order to explore the role of a magnetic field, we choose the compound (TMTTF) 2 Br with a sufficiently narrow spectrum of relaxation times because of its commensurate (antiferromagnetic) ground state [9,10]. This allows a systematic study of the equilibrium energy relaxation over almost one decade in temperature and a direct comparison to the local model of strong pinning without introducing an...

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mentioning

confidence: 99%

Interplay between Phase Defects and Spin Polarization in the Specific Heat of the Spin-Density-Wave Compound(TMTTF)2Brin a Magnetic Field

Mélin¹,

Lasjaunias²,

Sahling

et al. 2006

Phys. Rev. Lett.

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“…The crystallization current was increased to be proportional to the square of time [6]. Black needle crystals with the typical dimensions 6 £ 0:5 £ 0:2 mm 3 were obtained for up to x ¼ 0:2: The ratio of the Fe concentration to the Cl concentration in the samples was determined to be 1:4 by chemical analysis suggesting that the Fe atoms are embedded in the crystals in the FeCl 4 2 form substituted for AsF 6 2 . Magnetization was measured by means of a superconducting quantum interference device magnetometer (Quantum Design MPMS2).…”

Section: Methodsmentioning

confidence: 99%

“…The volume of FeCl 4 2 is about three times greater than that of AsF 6 2 . This difference in anion volume may cause a shortening of the Fe-Cl bond length and/or deformation of the tetrahedral symmetry of the FeCl 4 2 ions, resulting in an enhancement of the crystal field.…”

Section: Spin State Of Fe Impuritiesmentioning

confidence: 96%

Magnetization and electron spin resonance of Fe impurities in (TMTSF)2AsF6: magnetic-field-dependent interaction between impurity spins and spin-density waves

Yamaguchi

2004

Solid State Communications

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“…The presence of a localized impurity that weakly couples to the fermions causes Friedel oscillations, which are the rapid spatial variation (∼ e 2ik F x ) of the otherwise homogeneous density profile in a Luttinger liquid. In the Kubo formalism it is given as the density-density correlation function [20,21]. Egger and Grabert have studied Friedel oscillations in a Luttinger liquid with arbitrary interactions and arbitrary strengths of impurities [22].…”

Section: Friedel Oscillationsmentioning

confidence: 99%

“…There have been numerous attempts made to compute the correlation functions of fermionic ladder both numerically [10,11] and analytically [12][13][14][15]. H. J. Schulz investigated the phase diagram and excitation spectrum of two parallel Luttinger liquids coupled by single-particle arXiv:1704.01710v4 [cond-mat.str-el] 21 Sep 2017 hopping [16]. Patrick et.al.…”

Section: Introductionmentioning

confidence: 99%

The one step fermionic ladder

Das

Setlur

2017

Physica E: Low-dimensional Systems and Nanostructures

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The one step fermionic ladder refers to two parallel Luttinger Liquids (poles of the ladder) placed such that there is a finite probability of electrons hopping between the two poles at a pair of opposing points along each of the poles. The many-body Green function for such a system is calculated in presence of forward scattering interactions using the powerful non-chiral bosonization technique (NCBT). This technique is based on a non-standard harmonic analysis of the rapidly varying parts of the density fields appropriate for the study of strongly inhomogeneous ladder systems. The closed analytical expression for the correlation function obtained from NCBT is nothing but the series involving the RPA (Random Phase Approximation) diagrams in powers of the forward scattering coupling strength resummed to include only the most singular terms with the source of inhomogeneities treated exactly. Finally the correlation functions are used to study physical phenomena such as Friedel oscillations and the conductance of such systems with the potential difference applied across various ends.Comment: 13 pages,9 figures, 4 tables. arXiv admin note: text overlap with arXiv:1608.0582

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Theory of pinning of a spin-density wave by nonmagnetic impurities

Cited by 42 publications

References 16 publications

Interplay between Phase Defects and Spin Polarization in the Specific Heat of the Spin-Density-Wave Compound(TMTTF)2Brin a Magnetic Field

Interplay between Phase Defects and Spin Polarization in the Specific Heat of the Spin-Density-Wave Compound(TMTTF)2Brin a Magnetic Field

Magnetization and electron spin resonance of Fe impurities in (TMTSF)2AsF6: magnetic-field-dependent interaction between impurity spins and spin-density waves

The one step fermionic ladder

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