We investigate the feasibility of many candidate quantum Hall states for two-component bosons in the lowest Landau level. We identify interactions for which spin-singlet incompressible states occur at filling factors ν=2/3, 4/5, and 4/3, and partially spin-polarized states at filling factors 3/4 and 3/2, where "spin" serves as a generic label for the two components. We study ground states, excitations, edge states, and entanglement spectrum for systems with up to 16 bosons and construct explicit trial wave functions to clarify the underlying physics. The composite fermion theory very accurately describes the ground states as well as excitations at ν=2/3, 4/5, and 3/4, although it is less satisfactory for the ν=3/2 state. For ν=4/3 a "non-Abelian spin-singlet" state, which is the exact ground state of a three-body contact interaction, has been proposed to occur even for a two-body contact interaction; our trial wave functions are very accurate for the excitations of the three-body interaction, but they do not describe the excitations of the two-body interaction very well. Instead, we find that the ν=4/3 state is more likely to be a spin-singlet state of reverse-flux- attached composite fermions at filling ν*=4. We also consider incompressible states at integral filling factors ν=1 and 2. The incompressible state at ν=1 is shown to be well described by the parton-based Jain spin-singlet wave function, and the incompressible state at ν=2 as the spin-singlet state of reverse-flux-attached composite fermions at ν*=2, which provides an example of the bosonic integer topological phase.
|Original language||English (US)|
|Journal||Physical Review B - Condensed Matter and Materials Physics|
|Publication status||Published - Jun 24 2013|
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics