Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

arXiv:2201.08728 · Physical Review A

Fine structure of the stripe phase in ring-shaped Bose-Einstein condensates with spin-orbital-angular-momentum coupling

Y. M. Bidasyuk, K. S. Kovtunenko, O. O. Prikhodko

Published Feb 22, 2022• 12 citations
arXivHTMLPDF

Abstract

We report on a theoretical study of a ring-shaped Bose-Einstein condensate with Raman-induced spin-orbital-angular-momentum coupling. We analyze the structure of the ground state of the system depending on different physical parameters and reveal a peculiar fine structure within the stripe phase on the phase diagram. We demonstrate the existence of the predicted stripe subphases within a wide range of physical parameters, and their traceability through physical observables, and compare the results with several commonly used variational approximations. We also show that predicted subphases of the stripe phase can be observed within experimentally realizable conditions.

DOI
10.1103/physreva.105.023320

Related papers

Ground-state phase diagram and excitation spectrum of a Bose-Einstein condensate with spin-orbital-angular-momentum coupling

Ke-Ji Chen, Fan Wu, Jianshen Hu +1 more

We investigate the ground-state phase diagram and excitation spectrum of an interacting spinor Bose-Einstein condensate with spin-orbital-angular-momentum (SOAM) coupling realized in recent experiments by introducing atomic Raman transition with a pair of copropagating Laguerre-Gaussian laser beams that carry different orbital angular momenta (OAM) [Chen et al., Phys. Rev. Lett. 121, 113204 (2018) and Zhang et al., Phys. Rev. Lett. 122, 110402 (2019)]. Because of the ground-state degeneracy of the single-particle Hamiltonian at vanishing detuning, several angular-stripe phases, which are the superposition of states with different angular quantum numbers, appear in the phase diagram. However, these phases normally exist at small detuning, which makes them hard to be probed in experiments. We show that for a large OAM difference of the laser beams, an asymmetric kind of angular-stripe phase can exist even at large detuning. The excitation spectra in different phases exhibit distinct features: In the angular-stripe phase there exist two gapless bands corresponding to the broken $\mathrm{U}(1)$ and rotational symmetries, while in the half-skyrmion phase the gapless band exhibits a rotonlike structure. Our predictions of the angular-stripe phases and the low-energy excitations can be examined in recently realized Bose-Einstein condensates with SOAM coupling.

arXiv:1911.00255•Physical Review A•Jul 16, 2020•20 citations

Quantum phases of Bose-Einstein condensates with synthetic spin–orbital-angular-momentum coupling

Chunlei Qu, Kuei Sun, Chuanwei Zhang

The experimental realization of emergent spin-orbit coupling through laser-induced Raman transitions in ultracold atoms paves the way for exploring novel superfluid physics and simulating exotic many-body phenomena. A recent proposal with the use of Laguerre-Gaussian lasers enables another fundamental type of coupling between spin and orbital angular momentum (SOAM) in ultracold atoms. We hereby study quantum phases of a realistic Bose-Einstein condensate (BEC) with this synthetic SOAM coupling in a disk-shaped geometry, respecting radial inhomogeneity of the Raman coupling. We find that the experimental system naturally resides in a strongly interacting regime in which the phase diagram significantly deviates from the single-particle picture. The interplay between SOAM coupling and interaction leads to rich structures in spin-resolved position and momentum distributions, including a stripe phase and various types of immiscible states. Our results would provide a guide for an experimental investigation of SOAM-coupled BECs.

arXiv:1502.08052•Physical Review A•May 28, 2015•52 citations

Dynamics of spin–orbital-angular-momentum coupled Bose–Einstein condensates on a ring

Lin 林 Wen 文, Yihan Huang, Lei Zhao +2 more

Abstract We investigate the dynamics of a two-component Bose–Einstein condensate subject to spin–orbital-angular-momentum coupling and confined to a ring, via the variational approach. Adopting a single-mode approximation by assuming that the BEC carries a single angular momentum for SU(2)-symmetric spin interactions, the equations of motion for the variational parameters are derived. The phase diagram of the ground state in the plane of the Raman coupling and detuning contains three different phases which meet at a tricritical point, and the exact phase boundaries between the three phases are determined. Linear stability analysis shows that the stationary state is dynamically stable, and there exists an oscillation eigenmode with frequency determined by detuning, angular momentum, and Raman coupling. The time-evolution results indicate that the spin vector undergoes periodic rotation along a closed orbit on the Bloch sphere, which can be interpreted as a precession of the collective spin around an effective field determined by the Raman coupling strength, the detuning, and the angular momentum.

Chinese Physics B•Apr 3, 2026•0 citations

Angular stripe phase in spin-orbital-angular-momentum coupled Bose condensates

Xiao-Long Chen, Shi-Guo Peng, Peng Zou +2 more

We propose that a superfluid with supersolidlike properties, i.e., angular stripe phase, can be realized in a pancakelike 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, the half-skyrmion phase, and two different angular stripe phases.The stripe phases feature a modulated angular density-density correlation with a 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 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.

arXiv:1901.02595•Physical Review Research•Jul 28, 2020•27 citations

Symmetry breaking and phase transitions in Bose-Einstein condensates with spin–orbital-angular-momentum coupling

Yuxiong Duan, Y. M. Bidasyuk, A. Surzhykov

Theoretical study is presented for a spinor Bose-Einstein condensate, whose two components are coupled by copropagating Raman beams with different orbital angular momenta. The investigation is focused on the behavior of the ground state of this condensate, depending on the atom-light coupling strength. By analyzing the ground state, we have identified a number of quantum phases, which reflect the symmetries of the effective Hamiltonian and are characterized by the specific structure of the wave function. In addition to the well-known stripe, polarized, and zero-momentum phases, our results show that the system can support phases whose wave functions contain a complex vortex molecule. Such a molecule plays an important role in the continuous phase transitions of the system. The predicted behavior of vortex-molecule phases can be examined in cold-atom experiments using currently existing techniques.

arXiv:2010.10965•Physical Review A•Dec 24, 2020•20 citations

Phase transitions and elementary excitations in spin-1 Bose gases with Raman-induced spin-orbit coupling

Zeng-Qiang Yu

We study the ground-state phase diagram and the quantum phase transitions in spin-1 Bose gases with Raman-induced spin-orbit coupling. In addition to the Bose-Einstein condensates with uniform density, three types of stripe condensation phases that simultaneously break the U(1) symmetry and the translation symmetry are identified. The transitions between these phases are investigated, and the occurrences of the various tricritical points are predicted. The excitation spectra in the plane-wave phase and the zero-momentum phase show rich roton-maxon structures, and their instabilities indicate the tendency to develop the crystalline order. We propose the atomic gas of $^{23}\mathrm{Na}$ could be a candidate for observing the stripe condensate with high contrast fringes.

arXiv:1512.04091•Physical Review A•Mar 29, 2016•54 citations
We report on a theoretical study of a ring-shaped Bose-Einstein condensate with Raman-induced spin-orbital-angular-momentum coupling. We analyze the structure of the ground state of the system depending on different physical parameters and reveal a peculiar fine structure within the stripe phase on the phase diagram. We demonstrate the existence of the predicted stripe subphases within a wide range of physical parameters, and their traceability through physical observables, and compare the results with several commonly used variational approximations. We also show that predicted subphases of the stripe phase can be observed within experimentally realizable conditions.
We investigate the ground-state phase diagram and excitation spectrum of an interacting spinor Bose-Einstein condensate with spin-orbital-angular-momentum (SOAM) coupling realized in recent experiments by introducing atomic Raman transition with a pair of copropagating Laguerre-Gaussian laser beams that carry different orbital angular momenta (OAM) [Chen et al., Phys. Rev. Lett. 121, 113204 (2018) and Zhang et al., Phys. Rev. Lett. 122, 110402 (2019)]. Because of the ground-state degeneracy of the single-particle Hamiltonian at vanishing detuning, several angular-stripe phases, which are the superposition of states with different angular quantum numbers, appear in the phase diagram. However, these phases normally exist at small detuning, which makes them hard to be probed in experiments. We show that for a large OAM difference of the laser beams, an asymmetric kind of angular-stripe phase can exist even at large detuning. The excitation spectra in different phases exhibit distinct features: In the angular-stripe phase there exist two gapless bands corresponding to the broken U(1)\mathrm{U}(1)U(1) and rotational symmetries, while in the half-skyrmion phase the gapless band exhibits a rotonlike structure. Our predictions of the angular-stripe phases and the low-energy excitations can be examined in recently realized Bose-Einstein condensates with SOAM coupling.
The experimental realization of emergent spin-orbit coupling through laser-induced Raman transitions in ultracold atoms paves the way for exploring novel superfluid physics and simulating exotic many-body phenomena. A recent proposal with the use of Laguerre-Gaussian lasers enables another fundamental type of coupling between spin and orbital angular momentum (SOAM) in ultracold atoms. We hereby study quantum phases of a realistic Bose-Einstein condensate (BEC) with this synthetic SOAM coupling in a disk-shaped geometry, respecting radial inhomogeneity of the Raman coupling. We find that the experimental system naturally resides in a strongly interacting regime in which the phase diagram significantly deviates from the single-particle picture. The interplay between SOAM coupling and interaction leads to rich structures in spin-resolved position and momentum distributions, including a stripe phase and various types of immiscible states. Our results would provide a guide for an experimental investigation of SOAM-coupled BECs.
Abstract We investigate the dynamics of a two-component Bose–Einstein condensate subject to spin–orbital-angular-momentum coupling and confined to a ring, via the variational approach. Adopting a single-mode approximation by assuming that the BEC carries a single angular momentum for SU(2)-symmetric spin interactions, the equations of motion for the variational parameters are derived. The phase diagram of the ground state in the plane of the Raman coupling and detuning contains three different phases which meet at a tricritical point, and the exact phase boundaries between the three phases are determined. Linear stability analysis shows that the stationary state is dynamically stable, and there exists an oscillation eigenmode with frequency determined by detuning, angular momentum, and Raman coupling. The time-evolution results indicate that the spin vector undergoes periodic rotation along a closed orbit on the Bloch sphere, which can be interpreted as a precession of the collective spin around an effective field determined by the Raman coupling strength, the detuning, and the angular momentum.
We propose that a superfluid with supersolidlike properties, i.e., angular stripe phase, can be realized in a pancakelike 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, the half-skyrmion phase, and two different angular stripe phases.The stripe phases feature a modulated angular density-density correlation with a 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 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.
Theoretical study is presented for a spinor Bose-Einstein condensate, whose two components are coupled by copropagating Raman beams with different orbital angular momenta. The investigation is focused on the behavior of the ground state of this condensate, depending on the atom-light coupling strength. By analyzing the ground state, we have identified a number of quantum phases, which reflect the symmetries of the effective Hamiltonian and are characterized by the specific structure of the wave function. In addition to the well-known stripe, polarized, and zero-momentum phases, our results show that the system can support phases whose wave functions contain a complex vortex molecule. Such a molecule plays an important role in the continuous phase transitions of the system. The predicted behavior of vortex-molecule phases can be examined in cold-atom experiments using currently existing techniques.
We study the ground-state phase diagram and the quantum phase transitions in spin-1 Bose gases with Raman-induced spin-orbit coupling. In addition to the Bose-Einstein condensates with uniform density, three types of stripe condensation phases that simultaneously break the U(1) symmetry and the translation symmetry are identified. The transitions between these phases are investigated, and the occurrences of the various tricritical points are predicted. The excitation spectra in the plane-wave phase and the zero-momentum phase show rich roton-maxon structures, and their instabilities indicate the tendency to develop the crystalline order. We propose the atomic gas of 23Na^{23}\mathrm{Na}23Na could be a candidate for observing the stripe condensate with high contrast fringes.