Stabilization of nonlinear lattices: A route to superfluidity and hysteresis

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.

Loading ultracold atoms onto nonlinear Bloch states and soliton states in bichromatic lattices

“…Especially, the multi-component system would be a very nice platform. The appropriate combinations of the coherent control may produce gap solitons with spin-orbit coupling [50], stabilized NBWs [51], and so forth. Much remains to be studied.…”

Superfluidity breakdown of Rabi-coupled two-component Bose-Einstein condensates in optical lattices

“…The study of lattice superfluidity has been generalized from a single-component BEC to multiple components [24][25][26][27][28][29][30]. Multi-component BECs possess more degrees of freedom comparing with the single component.…”

“…Multi-component BECs possess more degrees of freedom comparing with the single component. The presence of inter-component interactions gives instabilities rich structures [28] and can stabilize certain Bloch states that are unstable in single-component analogues [27,30].…”