Transfer of solitons and half-vortex solitons via adiabatic passage

TL;DR

This paper demonstrates a method for transferring matter-wave solitons and half-vortex solitons in spin-orbit coupled Bose-Einstein condensates across optical lattice sites using adiabatic passage, leveraging flat band spectra and dark state mechanisms.

Contribution

It introduces a novel adiabatic transfer protocol for solitons in BECs utilizing flat band properties and a few-mode approximation, extending quantum control techniques to matter-wave solitons.

Findings

Successful transfer of solitons between lattice sites using adiabatic passage.

Implementation of the protocol in 1D and 2D optical lattices.

Capability to split and transfer wavepackets to multiple locations.

Abstract

We show that transfer of matter-wave solitons and half-vortex solitons in a spin-orbit coupled Bose-Einstein condensate between two (or more) arbitrarily chosen sites of an optical lattice can be implemented using the adiabatic passage. The underlying linear Hamiltonian has a flat band in its spectrum, so that even sufficiently weak inter-atomic interactions can sustain well-localized Wannier solitons which are involved in the transfer process. The adiabatic passage is assisted by properly chosen spatial and temporal modulations of the Rabi frequency. Within the framework of a few-mode approximation, the mechanism is enabled by a dark state created by coupling the initial and target low-energy solitons with a high-energy extended Bloch state, like in the conventional stimulated Raman adiabatic passage used for the coherent control of quantum states. In real space, however, the atomic transfer between initial and target states is sustained by the current carried by the extended Bloch state which remains populated during the whole process. The full description of the transfer is provided by the Gross-Pitaevskii equation. Protocols for the adiabatic passage are described for one- and two-dimensional optical lattices, as well as for splitting and subsequent transfer of an initial wavepacket simultaneously to two different target locations.