Chiral spin currents and spectroscopically accessible single merons in quantum dots

Abstract

We provide unambiguous theoretical evidence for the formation of correlation-induced isolated merons in rotationally-symmetric quantum dots. Our calculations rely on neither the lowest-Landau-level approximation, nor on the maximum-density-droplet approximation, nor on the existence of a spin-polarized state. For experimentally accessible system parameters, unbound merons condense in the ground state at magnetic fields as low as $B^{\ast }=0.2$ T and for as few as N = 3 confined fermions. The four-fold degenerate ground-state at $B^{\ast }$ corresponds to four orthogonal merons $|QC⟩$ characterized by their topological chirality $C$ and charge $Q$. This degeneracy is lifted by the Rashba and Dresselhaus spin-orbit interaction, which we include perturbatively, yielding spectroscopic accessibility to individual merons. We further derive a closed-form expression for the topological chirality in the form of a chiral spin current and use it to both characterize our states and predict the existence of other topological textures in other regions of phase space, for example, at N=5. Finally, we compare the spin textures of our numerically exact meron states to ansatz wave-functions of merons in quantum Hall droplets and find that the ansatz qualitatively describes the meron states.

4 pages, 5 figures; minor title change, typos fixed

References in corpus (14)

• Spontaneous Inter-layer Coherence in Double-Layer Quantum-Hall Systems I: Charged Vortices and Kosterlitz-Thouless Phase Transitions
• Universal quantum control of two-electron spin quantum bits using dynamic nuclear polarization
• Coherent spin manipulation in an exchange-only qubit
• Evidence of Skyrmion excitations about $\nu =1$ in n-Modulation Doped Single Quantum Wells by Inter-band Optical Transmission
• Skyrme Crystal In A Two-Dimensional Electron Gas
• Gate control of spin dynamics in III-V semiconductor quantum dots
• Gate-controlled spin-orbit interaction in a parabolic GaAs/AlGaAs quantum well
• Hartree-Fock Theory of Skyrmions in Quantum Hall Ferromagnets
• Evidence for Skyrmion crystallization from NMR relaxation experiments
• Controlling Spin Qubits in Quantum Dots
• Spectroscopic Evidence for the Localization of Skyrmions near Nu=1 as T->0
• Fractionalization into merons in quantum dots
• Meron ground states of quantum Hall droplets
• Chiral Spin Textures of Strongly Interacting Particles in Quantum Dots

Cited by in corpus (2)

• Unique Spin Vortices in Quantum Dots with Spin-orbit Couplings
• Tuning the Topological Features of Quantum-Dot Hydrogen and Helium by a Magnetic Field