Seminar “Theory of Condensed Matter”

Date and Time: Tuesday, 14 December 2021, at 4:00 PM

Venue: Blokhintsev lecture hall (4th floor), Bogoliubov Laboratory of Theoretical Physics, online seminar on Zoom

Link to join the seminar via Zoom

Semianr topic: “Nonlinear dynamical Casimir effect at weak deviations from stationarity”

Speaker: Dmitrii Trunin (MIPT, Moscow)

Abstract:

The dynamical Casimir effect is usually discussed in a quasiclassical approximation where interactions between the fields (i.e., nonlinearities of the equations of motion) are considered negligible. I will show that this approximation is not valid if the evolution time of the system is large enough. To that end, I will derive the effective Hamiltonian and calculate loop corrections to the particle flux in a massless scalar field theory with time-dependent Dirichlet boundary conditions and quartic self-interaction. In particular, I will consider a model that describes the continuous limit of the so-called Josephson material — a system, in which the dynamical Casimir effect can be modelled and measured experimentally. For simplicity, I will work in the limit of small deviations from equilibrium and use an analogue of the rotating wave approximation. In this approximation, the contribution of loop corrections to the number of created particles turns out to be comparable to the tree-level value.