Dzyaloshinskii-Moriya Interaction and Spiral Order in Spin-orbit Coupled Optical Lattices

We employ a self-consistent simulation approach based on quantum physics here to study the magnetism of antiferromagnetic skyrmions formed on manolayer nanodisk planes. We find that if the disk is small and the Dzyaloshinsky-Moriya (DM) interaction is weak, a single magnetic vortex may be formed on the disk plane. In such a case, when uniaxial anisotropy normal to the disk plane is further considered, the magnetic configuration remains unchanged, but the magnetization is enhanced in that direction, and reduced in other two perpendicular orientations. Very similarly, a weak external magnetic field normal to the disk plane cannot obviously affect the spin structure of the nanodisk; however, when it is sufficiently strong, it can destroy the AFM skyrmion completely. On the other hand, by increasing DM interaction so that the disk diameter is a few times larger than the DM length, more self-organized magnetic domains, such as vortices and strips, will be formed in the disk plane. They evolve with decreasing temperature, however always symmetric about a geometric axis of the square unit cell. We further find that in this case introducing normal magnetic anisotropy gives rise to the re-construction of AFM single-vortex structure or skyrmion on the disk plane, which provides a way to create and/or stabilize such spin texture in experiment.

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“…The Hamiltonian of this sort of nanosystems can be written as [10,[26][27][28][29][30][31][32][33][34] …”

Section: Modeling and Computational Algorithmmentioning

confidence: 99%

Numerical studies on antiferromagnetic skyrmions in nanodisks by means of a new quantum simulation approach

Liu

Ian

2016

Chemical Physics Letters

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“…By suitably coupling the atoms to laser fields, experimentalists have successfully created both Abelian (effective magnetic fields [4,5]) and non-Abelian gauge potentials (effective spin-orbit coupling [6]) in ultracold atomic systems, where the neutral atoms subjected to synthetic gauge fields exhibit a variety of interesting phenomena, including the Hofstadter fractal spectrum [7][8][9], spin-orbit coupled BoseEinstein condensates [6,[10][11][12][13][14][15][16][17], as well as spin-orbit coupled degenerate Fermi gases [18][19][20]. While most of these studies focus on the weakly interacting regime, the addition of a tunable optical lattice enables us to investigate the strongly correlated Mott insulating phases in the presence of gauge fields, where the interplay between strong interactions and synthetic gauge fields can give rise to exotic quantum magnetism that is difficult to access in solid-state physics [21][22][23][24][25][26][27][28][29][30].…”

Section: Introductionmentioning

confidence: 99%

Quantum magnetism of bosons with synthetic gauge fields in one-dimensional optical lattices: A density-matrix renormalization-group study

et al. 2014

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In this paper, we provide a comprehensive study of the quantum magnetism in the Mott insulating phases of the one-dimensional (1D) Bose-Hubbard model with Abelian or non-Abelian synthetic gauge fields, using the density-matrix renormalization-group (DMRG) method. We focus on the interplay between the synthetic gauge field and the asymmetry of the interactions, which give rise to a very general effective magnetic model: an XYZ model with various Dzyaloshinskii-Moriya (DM) interactions. The properties of the different quantum magnetic phases and phases transitions of this model are investigated.

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“…This vigorously activates intensive investigations on intriguing SO coupling effects for various correlated bosonic and fermionic systems [17][18][19][20][21][22][23] . In the presence of optical lattices, several theoretical groups have studied phase diagrams of the twocomponent bosonic Hubbard model mainly with Rashba SO couplings in two dimensions and with various approximations [24][25][26][27][28] . However, at present, the realizable SO coupling in experiments is along one direction.…”

Section: Introductionmentioning

confidence: 99%

Ferromagnetism in a two-component Bose-Hubbard model with synthetic spin-orbit coupling

Zhao

Hu²,

Chang

et al. 2014

Phys. Rev. A

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We study the effect of the synthetic spin-orbit coupling in a two-component Bose-Hubbard model in one dimension by employing the density-matrix renormalization group method. A ferromagnetic long-range order emerges in both Mott insulator and superfluid phases resulting from the spontaneous breaking of the Z2 symmetry, when the spin-orbit coupling term becomes comparable to the hopping kinetic energy and the intercomponent interaction is smaller than the intracomponent as well. This effect is expected to be detectable with the present realization of the synthetic spin-orbit coupling in experiments.

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Dzyaloshinskii-Moriya Interaction and Spiral Order in Spin-orbit Coupled Optical Lattices

Cited by 38 publications

References 49 publications

Numerical studies on antiferromagnetic skyrmions in nanodisks by means of a new quantum simulation approach

Numerical studies on antiferromagnetic skyrmions in nanodisks by means of a new quantum simulation approach

Quantum magnetism of bosons with synthetic gauge fields in one-dimensional optical lattices: A density-matrix renormalization-group study

Ferromagnetism in a two-component Bose-Hubbard model with synthetic spin-orbit coupling

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