Russian Academy of Sciences

Landau Institute for Theoretical Physics

Seminars

Regular seminars are held on Thursdays in the Kapitza Institute in Moscow and on Fridays at the scientific council of the Landau Institute in Chernogolovka.

Departments of the institute hold their own seminars; the topic are determined by the scientific orientation of the related department.

Seminars information is also sent via e-mail. If you want to receive seminar announcements, please subscribe.

Andreev conductance in disordered SF junctions with spin-orbit scattering

22 March in 11:30 at scientific council

M.E. Ismagambetov, P.M. Ostrovsky and M.V. Feigel’man

We present an idea of a new method to measure spin-orbit scattering rate in strongly disordered superconducting materials. The method is based upon specific Andreev reflection phenomenon at the boundary between superconductor and half-metal (fully polarized metallic ferromagnet). We demonstrate theoretically that spin-orbit scattering leads to a formation of a fluctuating in space triplet component of superconducting order parameter ∆_p(r) with zero average. However, Andreev conduction to half-metal is allowed due to mesoscopic fluctuations of this order parameter. The effect is expected to be strong in superconducting materials like amorphous InOx and others with not very large values of kF l product.

Point scatteres in the transmission eigenvalue problem.

22 March in 11:30 at scientific council (short)

P.G. Grinevich, R.G. Novikov

An energy level E in a quantum or wave scattering problem is called a transmission eigenvalue if one can prepare the incoming wave in such a way that no scattered wave is present. The dimension of the kernel of the scattering operator is called the transmission eigenvalue multiplicity. A typical results in this area states that for regular potentials with compact support the transmission eigenvalues 1) have finite multiplicity and 2) form a discrete set. We explain that such results have limited applicability because 1) In 1995 we proved that in dimension 2 one can construct regular decaying faster than any degree of the distance from the origin potentials, transparent at one energy. 2) Mutlipoint scatterers have transmission eigenvalues of infinite multiplicity at all energies.