Russian Academy of Sciences

Landau Institute for Theoretical Physics


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.

Microwave response of a chiral Majorana interferometer

14 May in 11:30 at scientific council

Alexander Shnirman (Karlsruhe Institute of Technology)

We consider an interferometer based on artificially induced topological superconductivity and chiral 1D Majorana fermions. The (non-topological) superconducting island inducing the superconducting correlations in the topological substrate is assumed to be floating. This allows probing the physics of interfering Majorana modes via microwave response, i.e., the frequency dependent impedance between the island and the earth. Namely, charging and discharging of the island is controlled by the time-delayed interference of chiral Majorana excitations in both normal and Andreev channels. We argue that microwave measurements provide a direct way to observe the physics of 1D chiral Majorana modes.

Two-impurity scattering in quasi-one-dimensional systems

14 May in 11:30 at scientific council

A.S. Ioselevich, N.S. Peshcherenko

In a quasi-one-dimensional system (a tube) with low concentration of defects $n$ the resistivity $\rho$ has peaks (van-Hove singularities) as a function of Fermi-energy. We show that due to non-Born scattering effects a deep narrow gap should appear just in the center of each peak. The resistivity at the bottom of a gap ($\rho_{\min}\propto n^2$) is dominated by scattering at rare ``twin-pairs'' of close defects, while scattering at solitary defects is suppressed. This effect is characteristic for multi-channel systems, it can not be observed in strictly one-dimensional one.