First-order pre-melting transition of vortex lattices

Carruzzo, Hervé M.; Yu, Clare C.

doi:10.1080/13642819808206400

Cited by 12 publications

(4 citation statements)

References 32 publications

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“…It is important to note that the parameters c 11 , c 66 , c 44 , γ, γ ′ , χ, and K, appearing in our model, are functions of the mean net defect density n 0 d , 38 which, within the supersolid phase, can in principle be determined through detailed microscopic calculations of the type presented in Ref. 20.…”

Section: Elastic Properties Of Supersolidsmentioning

confidence: 99%

Interstitials, vacancies, and dislocations in flux-line lattices: A theory of vortex crystals, supersolids, and liquids

Radzihovsky

1999

Phys. Rev. B

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We study a three dimensional Abrikosov vortex lattice in the presence of an equilibrium concentration of vacancy, interstitial and dislocation loops. Vacancies and interstitials renormalize the long-wavelength bulk and tilt elastic moduli. Dislocation loops lead to the vanishing of the longwavelength shear modulus. The coupling to vacancies and interstitials -which are always present in the liquid state -allows dislocations to relax stresses by climbing out of their glide plane. Surprisingly, this mechanism does not yield any further independent renormalization of the tilt and compressional moduli at long wavelengths. The long wavelength properties of the resulting state are formally identical to that of the "flux-line hexatic" that is a candidate "normal" hexatically ordered vortex liquid state.

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Section: Elastic Properties Of Supersolidsmentioning

confidence: 99%

Interstitials, vacancies, and dislocations in flux-line lattices: A theory of vortex crystals, supersolids, and liquids

Radzihovsky

1999

Phys. Rev. B

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“…Finally, the vortex lines go into the solid region below the irreversibility temperature, T irr . The existence of the flux-softened region might indicate that the melting transition of flux lines is a second-order phase transition [18,20] in our sample with correlated disordered defects.…”

Section: Resultsmentioning

confidence: 90%

“…Below T * , the effective activation energy increases rapidly with a decrease in temperature. Safar et al [17] and Carruzzo and Yu [18] claimed that the rapid increasing of effective energy with the decreasing temperature shows the vortex lines in a vortexglass state. According to the results reported by Kim et al [16], we consider that the downward curvature of −d(lnρ c )/d(1/T ) versus T curve might indicate that the vortex lines are in the TAFF region above temperature T * .…”

Section: Resultsmentioning

confidence: 99%

In-plane and out-of-plane magnetoresistivity in a MTG Er-doped YBCO crystal

Yang¹,

Wang²,

Zhang³

et al. 2002

Supercond. Sci. Technol.

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We have measured the temperature dependence of top and bottom voltage signals of a Y 0.8 Er 0.2 Ba 2 Cu 3 O 7−δ crystal in magnetic field up to 7.5 T parallel to the c-axis using the pseudo-flux-transformer method. The results show that in a dissipative regime the voltage signal on the side of the applied current contacts is more than that on the opposite side; meanwhile the bottom voltage signal shows a field-dependent peak effect near the critical temperature T c. We calculated the true resistivities ρ ab and ρ c of the crystal within an anisotropic model. The difference between the calculated ρ ab and ρ c and the experimental values ρ st ab and ρ st c is helpful in understanding flux dynamic behaviour. Based on the Yeshurun-Malozemoff model, we have investigated temperature and field dependences of effective activation energy along the ab-plane and c-axis obtained from the ρ ab (T) and ρ c (T), respectively. The temperature dependence of effective activation energy along the c-axis displays a good thermally activated flux flow (TAFF) behaviour. In the TAFF regime the field dependence of effective activation energy follows a power behaviour, U(H) = 4.24 × 10 4 H −1.1. The TAFF regime and the coupling between the layers have been discussed.

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“…[15] (b is a non-universal constant). This topological decoupling transition corresponds to the quartet-unbinding transition first proposed by Feigel'man et al [13] (or the supersolid transition [11]; a defect proliferation transition is also described in [16])-here, we establish a rigorous basis for the transition via the BKT scenario, accounting for the screening response of the pancake-vortex lattice. A finite Josephson coupling does not change result (9) if the extra Josephson energy ξ 2 def E J within the coherence area ξ 2 def ∼ n −1 d remains small, hence a 2 0 ε 2 ε 0 /d < T def ∼ gε 0 d, producing the condition ε < d/λ.…”

mentioning

confidence: 71%

Defect-Unbinding Transition in Layered Superconductors

Dodgson¹,

Geshkenbeǐn²,

Blatter

1999

Phys. Rev. Lett.

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We establish a new interstitial-vacancy unbinding transition of the Berezinskii-KosterlitzThouless type, transforming the three dimensional pancake vortex lattice of a decoupled layered superconductor into a defected solid. This transition is the natural finite-field extension of the vortex-anti-vortex unbinding transition establishing the zero-field superfluid stiffness. At finite Josephson coupling, the defect unbinding transition turns into a topological decoupling transition.PACS numbers: 74.60.Ec, 74.60.GeThe soft vortex matter in high-temperature layered superconductors exhibits a fascinating rich phase diagram with a variety of phase transitions modifying the various intra-and interplanar correlations. These include a melting transition from a line solid to a line liquid [1][2][3], a sublimation transition taking the solid into a pancake vortex gas [4], and a decoupling transition [4][5][6][7] destroying the superconducting coherence between the planes. In this letter we concentrate on the decoupled limit where the three-dimensional (3D) nature of the vortex system is solely due to the long range electromagnetic interaction between the pancake vortices. We establish that in the crystal phase there is a Berezinskii-Kosterlitz-Thouless (BKT) phase transition which separates the pancakevortex lattice from a defected 3D solid with a finite density of free interstitials and vacancies, see The vortex lattice in layered superconductors is "soft" and melts at low temperatures; for fields B > B λ = Φ 0 /λ 2 (λ = penetration depth) the transition is governed by the shear interaction between pancake vortices in the same layer and thus is close to the two-dimensional dislocation-mediated BKT melting in the individual layers [8]. The 3D nature of the transition becomes explicit only at low fields B < B λ , where the electromagnetic (tilt) interaction between pancake vortices in different layers dominates over the intralayer (shear) interaction due to the planar currents [4]. Here, we study another thermodynamic property of the pancake-vortex latticeits susceptibility to the formation of free defects in the form of pancake-vortex interstitials and vacancies. It has recently been shown [9] for the pancake-vortex lattice in layered decoupled superconductors that the self-energy of (and the logarithmic interaction between) vacancies and interstitials is strongly screened due to the relaxation of the vortex lattice surrounding the defects. We find that the corresponding interstitial-vacancy pair creation can be understood in terms of a simple vortex-anti-vortex pair creation in a superconductor with a vortex-induced suppression of the superfluid density. The usual zero-field BKT transition establishing the superfluid stiffness of the individual superconducting layers [10] therefore has its counterpart at finite fields in the form of interstitialvacancy unbinding in the vortex solid.We start from a rigid vortex lattice in a decoupled layered superconductor and move one pancake by the distance R within the same layer to prod...

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First-order pre-melting transition of vortex lattices

Cited by 12 publications

References 32 publications

Interstitials, vacancies, and dislocations in flux-line lattices: A theory of vortex crystals, supersolids, and liquids

Interstitials, vacancies, and dislocations in flux-line lattices: A theory of vortex crystals, supersolids, and liquids

In-plane and out-of-plane magnetoresistivity in a MTG Er-doped YBCO crystal

Defect-Unbinding Transition in Layered Superconductors

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