ELFT HÍRADÓ

[Janos Asboth <asboth.janos AT ttk.bme.hu>]

Meghívó

BME Elméleti Fizika Szeminárium,

márc. 31. péntek 10h15,

1111 Budapest, Budafoki út 8., BME F III. magasföldszint 01.,
Elméleti Fizika Tanszék szemináriumi szoba

Guba Zoltán (BME Elm. Fiz. Tanszék):
Weyl points in ball-and-spring mechanical systems

Degeneracy points of parameter-dependent Hermitian matrices play a
fundamental role in quantum physics, as illustrated by the concept of Berry
phase in quantum dynamics, the Weyl semimetals in condensed-matter physics,
and the robust ground-state degeneracies in topologically ordered quantum
systems. Here[1], we construct simple ball-and-spring mechanical systems,
whose eigenfrequency degeneracies mimic the behaviour of degeneracy points
of electronic band structures. These classical-mechanical arrangements can
be viewed as de-quantized versions of Weyl Josephson circuits, i.e.,
superconducting nanostructures proposed recently to mimic band structure
effects of Weyl semimetals. In the mechanical setups we study, we identify
degeneracy patterns beyond simple Weyl points, including the chirality flip
effect and a quadratic degeneracy point. Our theoretical work is a step
toward simple and illustrative table-top experiments exploring topological
and differential geometrical aspects of physics.

[1]: Z Guba, Gy Frank, G Pintér, A Pályi: Weyl points in ball-and-spring
mechanical systems,  arXiv:2302.08241

Minden érdeklődőt szeretettel várunk.
Asbóth János,
 szemináriumi koordinátor