London penetration depth

London Bullion Market Association, silver specifications by, 22 649 London coherence length, 23 806 London equations, 23 806 London-Norris equations, 23 845 London penetration depth, 23 805, 806 London s forces, 12 4 15 213 21 602-604 ... 

First we review some typical materials parameters obtained from measurements on randomly oriented ceramics (6-7). Since the YBaCuO structure (5) and electronic properties 81 are highly anisotropic, the orientationally-averaged values obtained from studies of ceramics are only an initial indication until more complete experimental results on single crystals and oriented films and ceramics become available. For material with a resistivity just above the transition of 400 /xficm, a Hall carrier density of 4xl021cm , and dHc2/dT of 2 T/K (6-7). one deduces a BCS coherence length (0) of 1-4 nm, a London penetration depth A(0) of 200 nm, a mean free path t of 1.2 nm, a thermodynamic critical field Hc(0) of 1 T (10000 Oe) and an upper critical... 

From the theory of the diamagnetic response the London penetration depth of the holon superconductor is... 

London penetration depth Xj twist penetration depth... 

London penetration depth, At, is the penetration length of the twist distortion, and the equivalent of the coherence length, co, is the correlation length of the smectic phase. In a screw dislocation, the core of the defect approximates to the smectic correlation length and a twist of 90° to the penetration depth, see Fig. 14(b). 

A = energy gap Ab = screening field Al = London penetration depth GL = Ginzburg-Landau coherence length lo = BCS coherence length... 

Further results from TF-p,SR studies on UPd2Al3 concern superconducting properties that are outside this review. We mention the approximately isotropic London penetration depth ( 5000A) and the ratio %/T 10 (T being the Fermi tenqierature) which is one order of magnitude larger than that for simple metallic BCS superconductors (W.D. Wu et al. 1994b). 

Properties and microscopic parameters characterizing the normal and superconducting states of polycrystalline heavy-fermion superconductors T, from speciflc-heat measurements B and, slopes of upper and lower critical-field curves at T p , normal-state (T — 0) resistivity 1, total mean free path I, Ginzburg-Landau coherence length A, London penetration depth k, Ginzburg-Landau parameter 0) B, , B j(T—>0). The other... 

Measurements of the London penetration depth A(T) point to the existence of aniostropic superconducting phases in UBejj (Einzel et al. 1986) and CeCu2Si2 (Gross et al. 1988), as well. Figure 76 demonstrates for the former system clear deviations from the temperature dependence expected for an ordinary, isotropic superconductor. As an explanation, it has been proposed (Gross et al. 1986, Millis 1987) to use the standard connection between the condensate velocity and the electromagnetic potentials,... 

---