Segue abaixo informações sobre o Colóquio que será apresentado nesta sexta-feira, dia 31/03/2023

 

Palestrante:
Alexei Vagov, ITMO University – Center of Quantum Metamaterials

 

Título:

Exotic magnetic flux patterns in superconductors between type I and II

 

Resumo:

The Ginzburg-Landau theory distinguishes two superconductivity types: ideally diamagnetic type-I materials and type-II superconductors that allows magnetic flux forming the mixed state with Abrikosov vortices. However, this dual classification does not exhaust all possibilities even for the standard BCS theory, which reveals a special regime of inter-type (IT) superconductivity. It has very distinct characteristics and should be regarded as a separate superconductivity type. Its intermediate mixed state (IMS) carries a manifold of exotic vortex patterns ranging from clusters of vortex lattices, to vortex stripes, labyrinths, and liquid droplets. It is shown that the IT superconductivity regime is a generic phenomenon generated by proximity to the super-critical Bogomolnyi point, at which the superconductive state is self-dual and infinitely degenerate. The IMS phase diagram is determined by the degeneracy-breaking mechanism, and is not sensitive to the microscopic details of the system. The generic nature of the phenomenon explains qualitatively similar vortex patterns appearing in a wide class of superconductors including single- and many-band compounds, magnetic materials, thin films and hybrid devices. These link superconductivity with the world of spontaneously emerging complexity.

 

Local / Horário: 
Auditório do Departamento de Física / 16h00

Dia 31/Março/2023

 

Short-Bio:

Dr. rer. nat. habil. (Doctor of Science)

POSITIONS: Chair, Centre of Quantum Metamaterials Department of Electronics and Applied Mathematics (MIEM), HSE Research University, Russia; Privat Dozent, Department of Physics, Bayreuth University, Germany; Lead Scientist, Department of Physics, ITMO Sankt-Peterburg University, Russia; Chair of the international laboratory "Centre of Quantum Metamaterial", coordination of research activities of the centre, teaching undergraduate/postgraduate students, supervision of student research.

CURRENT RESEARCH INTERESTS

1. Ultra-fast real-time coherent quantum dynamics of few- and many-particle condensed matter systems driven far from equilibrium; quantum dissipation and non-Markovian processes; decoherence and relaxation; mechanisms to reach thermodynamic equilibrium in quantum systems;

2. Quantum optics; light-matter interactions; quantum electrodynamics in confined systems, many particle collective light-matter excitations, quantum and classical, (e.g. plasmons and plasmon polaritons); quantum dynamics of strongly coupled light-matter many-particle systems;

3. Electronic, dynamic and optical properties of low-dimensional semiconductor and graphene-like materials;

4. Quantum condensates; unconventional magnetic response in multi-band and nano-sized superconductors; BCS-BEC crossover in superconductors.

5. Developing theory methods: real-time path integral and tensor-network propagation methods for the first principle calculations of non-linear quantum dynamics of complex many-particle systems, novel perturbative and semiclassical methods for quantum condensates and other problems in condensed matter physics.