Stabilization of Nonlinear Lattices: A Route to Superfluidity and Hysteresis

TL;DR

This paper demonstrates that two-component Bose-Einstein condensates in nonlinear lattices can be stabilized through coherent linear coupling, enabling superfluidity and hysteresis phenomena observable with current experimental techniques.

Contribution

It introduces a method to stabilize Bloch states in nonlinear lattices using coherent linear coupling, revealing new superfluid and hysteretic behaviors.

Findings

Two-component BECs can be stabilized in nonlinear lattices.

Strong coherent coupling stabilizes the lowest Bloch band.

Hysteretic loop-like structures in Bloch bands are observed.

Abstract

The Bloch states of a Bose-Einstein condensates (BECs) in pure nonlinear lattices (NLs) are dynamically unstable, so that they cannot show superfluidity. We overcome this problem by finding that the two-component BECs in NLs can be stabilized by the coherent linear coupling. Furthermore, in the limit of the strong coherent coupling, the lowest Bloch band in the whole Brillouin zone can be dynamically stable. We also find a hysteretic behavior with loop-like structure in the Bloch band resembling the so-called "swallowtail" loop. The dynamical stabilization and hysteretic behavior can be observed in experiments by current technology.