Quantum fluctuations in nonlinear Schrödinger breathers

O. V. Marchukov, Institut für Angewandte Physik, Technical University of Darmstadt, Germany

Solitons are nonlinear waves that show up in many different fields of physics: From solitary water waves to Langmuir waves in plasmas, the formation of solitons attracts the interest of theoreticians and experimentalists alike. In this talk, we focus on the two-soliton breathers – nonlinear superposition of two bright solitons – in one-dimensional Bose gases that were recently obtained experimentally [2,4]. We present the linearization approach that allows one to evaluate quantum fluctuations of the parameters that define the solitonic solutions.

Furthermore, we demonstrate the uncertainty relations of the parameters for both the fundamental soliton and breather. We also discuss the dissociation of breather under both the influence of an external perturbation [1] and the quantum fluctuations of relative velocity. The former allows us to evaluate the breather dissociation time, i.e. the time it takes for the constituent solitons to be significantly separated. Without an external perturbation, the dissociation does not occur in the mean-field regime, thus making the dissociation time a potentially observable manifestation of quantum effects [3].

References

[1] O. V. Marchukov et al., Phys. Rev. A 99, 063623 (2019).
[2] A. Di Carli et al., Phys. Rev. Lett. 123, 123602 (2019).
[3] O. V. Marchukov et al., Phys. Rev. Lett. 125, 050405 (2020).
[4] D. Luo et al., Phys. Rev. Lett. 125, 183902 (2020).