Beecroft Building, Department of Physics, University of Oxford, Parks Road, Oxford, OX1 3PU
Professor Thomas Gasenzer, Kirchhoff-Institut fur Physik, University of Heidelberg
Abstract
A quantum many-body system driven far from equilibrium via a parameter quench can show universal
dynamics, characterized by self-similar spatio-temporal scaling, associated with the approach to a non-thermal
fixed point [1–4]. Non-linear excitations such as solitons or vortices, rogue waves, and instantons play a key role
in the time evolution of such systems [5–8]. I will introduce to the concept of non-thermal fixed points and
discuss developing and decaying quantum turbulence, associated with an anomalous nonthermal fixed point,
exhibiting aspects equivalent as well as different from classical fluids [7]. A low-energy effective sine-Gordon
type represents a possible approach to the specific universality class of such anomalous fixed points,
characterized by sub-diffusive scaling [9,10].
[1] A. N. Mikheev, I. Siovitz, and T. Gasenzer, “Universal dynamics and non-thermal fixed points in quantum fluids far from
equilibrium,” Eur. Phys. J. Spec. Top. 232, 3393 (2023). Doi: https://dx.doi.org/10.1140/epjs/s11734-023-00974-7.
[2] M. Prüfer, P. Kunkel, H. Strobel, et al., “Observation of universal dynamics in a spinor Bose gas far from equilibrium,” Nature
563, 217 (2018). Doi: https://dx.doi.org/10.1038/s41586-018-0659-0.
[3] J. A. P. Glidden, C. Eigen, L. H. Dogra, T. A. Hilker, R. P. Smith, and Z. Hadzibabic, “Bidirectional dynamic scaling in an
isolated Bose gas far from equilibrium,” Nature Physics 17, 457 (2021). Doi: https://dx.doi.org/10.1038/s41567-020-01114-x.
[4] S. Erne, R. Bücker, T. Gasenzer, J. Berges and J. Schmiedmayer, Universal dynamics in an isolated one-dimensional Bose gas far
from equilibrium, Nature 563, 225 (2018). Doi: https://dx.doi.org/10.1038/s41586-018-0667-0.
[5] M. Karl and T. Gasenzer, „Strongly anomalous non-thermal fixed point in a quenched two-dimensional Bose gas“, New J. Phys.
19, 093014 (2017). Doi: http://dx.doi.org/10.1088/1367-2630/aa7eeb.
[6] N. Rasch, L. Chomaz, and T. Gasenzer, „Anomalous non-thermal fixed point in a quasi-two-dimensional dipolar Bose gas”, Phys.
Rev. A 112, 053310 (2025). Doi: https://dx.doi.org/10.1103/x2rj-ptgy.
[7] N. Rasch and T. Gasenzer, „Decaying superfluid turbulence near an anomalous non-thermal fixed point“, arXiv:2509.21285. Doi:
https://arxiv.org/abs/2509.21285.
[8] I. Siovitz, S. Lannig, Y. Deller, H. Strobel, M. K. Oberthaler, and T. Gasenzer, “Universal dynamics of rogue waves in a
quenched spinor bose condensate,” Phys. Rev. Lett. 131, 183402 (2023). Doi:
https://dx.doi.org/10.1103/PhysRevLett.131.183402.
[9] P. Heinen, A.N. Mikheev, T. Gasenzer, „Anomalous scaling at non-thermal fixed points of the sine-Gordon model“, Phys. Rev. A
107, 043303 (2023). Doi: https://dx.doi.org/10.1103/PhysRevA.107.043303.
[10] I. Siovitz, A.-M. Glück, Y. Deller, et al., “Double Sine-Gordon effective theory for universal dynamics of a spin-1 Bose gas”
Phys. Rev. A 112, 02304 (2025). Doi: http://dx.doi.org/10.1103/df5w-3yfd.