SciPost Phys. 12, 160 (2022) ·
published 13 May 2022
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· pdf
We investigate macroscopic behaviors of fluctuating domain walls in
nonequilibrium open systems with the help of the effective field theory based
on symmetry. Since the domain wall in open systems breaks the translational
symmetry, there appears a gapless excitation identified as the Nambu-Goldstone
(NG) mode, which shows the non-propagating diffusive behavior in contrast to
those in closed systems. After demonstrating the presence of the diffusive NG
mode in the $(2+1)$-dimensional dissipative Josephson junction, we provide a
symmetry-based general analysis for open systems breaking the one-dimensional
translational symmetry. A general effective Lagrangian is constructed based on
the Schwinger-Keldysh formalism, which supports the presence of the gapless
diffusion mode in the fluctuation spectrum in the thin wall regime. Besides, we
also identify a term peculiar to the open system, which possibly leads to the
instability in the thick-wall regime or the nonlinear Kardar-Parisi-Zhang
coupling in the thin-wall regime although it is absent in the Josephson
junction.
Dr Fujii: "------------------------------..."
in Submissions | report on Effective field theory of fluctuating wall in open systems: from a kink in Josephson junction to general domain wall