Broken-symmetry ground states in ν=2 bilayer quantum Hall systems
Abstract
We report on a study of a bilayer two-dimensional electron gas at Landau-level filling factor ν=2. The system exhibits both magnetic and spontaneous interlayer phase coherence broken symmetries. We propose a three-parameter Slater-determinant variational wave function which describes the ground state over the full range of bias-potential (ΔV), Zeeman coupling (Δz), and interlayer tunneling amplitude (Δt) strengths. Broken-symmetry states occur inside a volume in this three-dimensional phase diagram near the Δ2z=Δ2V+Δ2t surface. We have obtained analytic results for the intersections of the phase diagram with the Δt=0, Δz=0, and ΔV=0 planes and show that the differential capacitance of the bilayer system is singular at the phase boundary.
- Publication:
-
Physical Review B
- Pub Date:
- September 1999
- DOI:
- 10.1103/PhysRevB.60.8817
- arXiv:
- arXiv:cond-mat/9903318
- Bibcode:
- 1999PhRvB..60.8817M
- Keywords:
-
- 73.40.Hm;
- 73.20.Dx;
- 75.30.Kz;
- Magnetic phase boundaries;
- Condensed Matter - Mesoscale and Nanoscale Physics
- E-Print:
- 26 pages, 8 figures, submitted to Phys. Rev. B