Seminars
Regular seminars are held on Fridays at the scientific council of the Landau Institute in Chernogolovka. Also joint ITP - Chinese Academy of Sciences online colloquium is held online.
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.
Dissipation-induced nonlocal phase-coherent transport in a topological superconductor
6 November in 11:30 at scientific council
S.V. Aksenov, M. S. Shustin, I. S. Burmistrov
Nonlocal phase-coherent transport via Majorana bound states, so-called teleportation, requires Coulomb blockade to suppress local Andreev reflection. We show that dissipation can replace the need for Coulomb blockade. We study a Kitaev chain coupled to a Markovian bath and identify a regime where the magnitude of nonlocal conductance contribution reach the local one. In this regime, the lowest-energy subspace is maximally mixed, reminiscent of a directly grounded nontrivial topological superconductor. Phase coherence is confirmed by Aharonov-Bohm oscillations. Our results establish dissipation as a tool for controlling quantum teleportation in Majorana systems.
Free-Field Construction of Heterotic String Compactified on Calabi–Yau Orbifolds via Correspondence with N=2 SCFT Minimal Models
13 November in 11:30 at scientific council
G. Makarov,A. Belavin, D. Gepner
We establish a correspondence between the free-field construction and the minimal-model construction of the Calabi–Yau sector of the four-dimensional heterotic string compactified on Berglund–Hübsch type Calabi–Yau manifolds and their orbifolds. For Fermat-type polynomials the Calabi–Yau vertex operators expressed in terms of free fields are shown to correspond to products of primary fields of ????=2 minimal models. Using this correspondence we verify modular invariance of the free-field construction and extend it to Berglund–Hübsch Calabi–Yau orbifolds, deriving the conditions on complete vertex operators that parallel those of the minimal-model construction [1].
[1] A. Belavin, D. Gepner, G. Makarov, Free-Field Construction of Heterotic String Compactified on Calabi–Yau Orbifolds via Correspondence with N=2 SCFT Minimal Models, Nucl. Phys. B 117668 (2026).
Berry Curvature Effect in Anomalous Transport
27 November in 11:30 at scientific council
V.P.Mineev
The Berry curvature effect in anomalous transport driven by statistical forces such as the gradient of temperature or chemical potential has been developed by Di Xiao et al in Phys. Rev. Lett. 97, 026603 (2006). This theory operates with spinless fermions. So, the Berry curvature, corresponding magnetic moment of wave packets and the magnetic field dependent density of states originate from the electron orbital degrees of freedom. We present an alternative derivation of the Berry curvature effect on charge, heat and as well on thermalelectric currents in altermagnets and noncentrosymmertric metals where the electron band dispersion possesses spin dependent band splitting.
Band splitting in the altermagnet CrSb
27 November in 12:10 at scientific council
V.P.Mineev
The band spin splitting in the hexagonal altermagnet CrSb is established using the magnetic group formalism that allows to find the additional spin splitting missed in the frame of the exchange approximation.
Phys.Rev.B 114, 065130 (2026).
Phys.Rev.B 114, 065130 (2026).
Altermagnets versus Antiferromagnets
27 November in 12:50 at scientific council
V.P.Mineev
Altermagnets are substances with a momentum-dependent spin splitting of electron bands due to a specific crystal structure that is invariant under time reversal only in combination with rotations and reflections. The developed phenomenological approach allows to obtain a spectrum of electron bands in altermagnets corresponding to antiferromagnets with the same symmetry. We consider antiferromagnetic, weak ferromagnetic, and ferrimagnetic structures. The calculated Berry curvature of electron bands in the alterrmarnet with zero spontaneous magnetisation occurs an odd function of momentum whereas it is even in a weak ferromagnetic state. The Berry curvature in ferrimagnetic state is equal to zero.
Construction of mirror pairs of Berglund-Hubsch-type Calabi-Yau orbifolds
4 December in 11:30 at scientific council (short)
A. Belavin, S. Aleshin
In this work, we propose an algorithm for constructing orbifolds of Calabi-Yau manifolds of Berglund-Hubsch type. This approach allows us to obtain all mirror pairs for Calabi-Yau manifolds of this type. As an example, we considered one of the Fermat-type models, for which all its orbifolds and their mirror pairs were found, and also for each orbifold the number of generations of quarks and leptons was found, as well as the number of types of particles participating only in gravitational interaction, i.e. dark matter particles.
Analytical approximations of dispersion relations and complex dynamics on the Fermi surfaces
11 December in 11:30 at scientific council
A.Ya. Maltsev
We discuss the electron dynamics on complex Fermi surfaces in the presence of rather strong magnetic fields. Such electron dynamics can be quite complex, and its most complex regimes are associated with the dynamics of analytic systems on Riemann surfaces. In general,
this dynamics is associated with the most complex angular diagrams
describing the behavior of conductivity in strong magnetic fields. The
detection of such diagrams is of great interest, however, it requires a very
careful selection of experimental parameters. Here we discuss the
emergence of such diagrams for dispersion relations arising in tight-binding
and nearly free electron models in the cubic lattice case.
The Novikov problem for superposition of symmetric periodic hotentials
11 December in 12:30 at scientific council (short)
A.Ya. Maltsev
We consider the Novikov problem, i.e. the problem of describing the global geometry of the level sets of quasiperiodic functions in the plane, for potentials formed by the superposition of periodic potentials that share the same rotational symmetry. For this class of potentials, it is shown that unbounded components of the level sets can exist at only a single energy level; in this respect, such potentials are similar to random potentials in the plane.