ar X iv : c on d - m at / 9 70 30 28 v 1 3 M ar 1 99 7 In - plane optical response of Bi 2 Sr 2 CuO 6

ar X iv : c on d - m at / 9 30 30 27 v 1 1 5 M ar 1 99 3 cond -

The phase variation of the superconducting gap over the (normal) Fermi surface of the high-temperature superconductors remains a significant unresolved question. Is the phase of the gap constant, does it change sign, or is it perhaps complex? A detailed answer to this question would provide important constraints on various pairing mechanisms. Here we propose a new method for measuring the relat...

ar X iv : c on d - m at / 9 60 30 39 v 1 6 M ar 1 99 6 Theory for Spin - Polarized Oscillations in Nonlinear Magneto - Optics due to Quantum Well States

Using an electronic tight-binding theory we calculate the nonlinear magneto-optical response from an x-Cu/1Fe/Cu(001) film as a function of frequency and Cu overlayer thickness (x=3. . .25). We find very strong spinpolarized quantum well oscillations in the nonlinear magneto-optical Kerr effect (NOLIMOKE). These are enhanced by the large density of Fe d states close to the Fermi level acting as...

ar X iv : s ol v - in t / 9 70 30 03 v 1 6 M ar 1 99 7 ON THE POINT TRANSFORMATIONS FOR THE SECOND ORDER DIFFERENTIAL EQUATIONS

Point transformations for the ordinary differential equations of the form y ′′ = P (x, y) + 3 Q(x, y) y ′ + 3 R(x, y) (y ′) 2 + S(x, y) (y ′) 3 are considered. Some classical results are resumed. Solution for the equivalence problem for the equations of general position is described.

ar X iv : c on d - m at / 9 30 70 20 v 2 2 1 Ju l 1 99 3 Dissipation of the 3 He A → B Transition

A rigorous hydrodynamic theory of the A-B transition is presented. All dissi-pative processes are considered. At low interface velocities, those occurring on hy-drodynamic length scales, not considered hitherto, are most probably the dominant ones.

ar X iv : c on d - m at / 9 70 80 30 v 1 [ co nd - m at . s up r - co n ] 5 A ug 1 99 7 1