# Angular Stripe Phase in Spin-Orbital-Angular-Momentum Coupled Bose Condensates

## TL;DR

This paper predicts a novel angular stripe superfluid phase in spin-orbital-angular-momentum coupled Bose gases, characterized by modulated angular density correlations and distinct collective excitations, which can be tested in current cold-atom experiments.

## Contribution

It introduces the angular stripe phase in spin-orbital-angular-momentum coupled Bose gases and maps its rich phase diagram with experimental relevance.

## Key findings

- Identification of the angular stripe phase with high contrast.
- Distinct collective mode behaviors in different phases.
- Phase diagram including vortex-antivortex, skyrmion, and stripe phases.

## Abstract

We propose that novel superfluid with supersolid-like properties - angular stripe phase - can be realized in a pancake-like spin-1/2 Bose gas with spin-orbital-angular-momentum coupling. We predict a rich ground-state phase diagram, including the vortex-antivortex pair phase, half-skyrmion phase, and two different angular stripe phases. The stripe phases feature modulated angular density-density correlation with sizable contrast and can occupy a relatively large parameter space. The low-lying collective excitations, such as the dipole and breathing modes, show distinct behaviors in different phases. The existence of the novel stripe phase is also clearly indicated in the energetic and dynamic instabilities of collective modes near phase transitions. Our predictions of the angular stripe phase could be readily examined in current cold-atom experiments with $^{87}$Rb and $^{41}$K.