Emergent gauge field and the Lifshitz transition of spin-orbit coupled bosons in one dimension

Abstract

In the presence of strong spin-independent interactions and spin-orbit coupling, we show that the spinor Bose liquid confined to one spatial dimension undergoes an interaction- or density-tuned quantum phase transition similar to one theoretically proposed for itinerant magnetic solid-state systems. The order parameter describes broken Z 2 inversion symmetry, with the ordered phase accompanied by non-vanishing momentum which is generated by fluctuations of an emergent dynamical gauge field at the phase transition. This quantum phase transition has dynamical critical exponent z ≃ 2, typical of a Lifshitz transition, but is described by a nontrivial interacting fixed point. From direct numerical simulation of the microscopic model, we extract previously unknown critical exponents for this fixed point. Our model describes a realistic situation of 1D ultracold atoms with Raman-induced spin-orbit coupling, establishing this system as a platform for studying exotic critical behavior of the Hertz-Millis type.

Strongly interacting spin-orbit coupled Bose-Einstein condensates in one dimension

“…In the strongly correlated regime [42,43], the SOC spin-1 Bose-Hubbard model at the odd integer filled Mott lobes can be mapped to an insulating quantum spin-1 magnet in a helical magnetic field which tunes a quantum phase transition [44,45]. However, on the other hand, the strongly correlated superfluid regime of dilute bosons in 1D in the presence of a SOC has not yet received much attention, despite the potentially rich magnetic phenomena due to the spin-1 nature of the problem, which extends beyond the spin-1/2 case [32,46].…”