ELFT HÍRADÓ

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

Meghívó

BME Elméleti Fizika Szeminárium,

márc. 21 péntek 10h15,
1111 Bp., Budafoki út 8., BME FIII. magasföldszint 1, szemináriumi szoba

Krasznai Anna (BME Elm. Fiz. tanszék):
Confinement and false vacuum decay on the Potts quantum spin chain

Confinement is a central concept in the theory of strong interactions,
which leads to the absence of quarks (and gluons) from the spectrum of
experimentally observed particles. The underlying mechanism is based on a
linear potential, which can also be realised in condensed matter systems. A
one-dimensional example with a great analogy to quantum chromodynamics is
the mixed-field three-state Potts quantum spin chain in the ferromagnetic
regime. Compared to the analogous setting for the Ising spin chain, the
Potts model has a much richer phenomenology and non-equilibrium dynamics,
which originates partly from baryonic excitations in the spectrum and
partly from the various possible relative alignments of the initial
magnetisation and the longitudinal field in a global quantum quench. In my
presentation, I will discuss how we obtain the low-lying excitation
spectrum by combining semi-classical approximation and exact
diagonalisation, and how the results can be applied to explain the various
dynamical behaviours we observe in numerical simulations. Besides
recovering dynamical confinement, as well as Wannier-Stark localisation due
to Bloch oscillations similar to the Ising chain, a novel feature is the
presence of baryonic excitations in the quench spectroscopy. In addition,
when the initial magnetisation and the longitudinal field are misaligned,
both confinement and Bloch oscillations only result in partial
localisation, with some correlations retaining an unsuppressed light-cone
behaviour together with a corresponding growth of entanglement entropy.

Reference:

[1] O. Pomponio, A. Krasznai and G. Takács, “ Confinement and false vacuum
decay on the Potts quantum spin chain,” Scipost Phys. 18 (2025) 082

Minden érdeklődőt szeretettel várunk.
Asbóth János,
 szemináriumi koordinátor