Workshop 2025: Anomalous Reentrant Fractional Quantum Hall Effect at 5/2 in GaAs at Moderate Landau Level Mixing

Session Information

Location: Lecture room F3213 - 05
Day: Wednesday, 14 May
Time: 18:00 - 19:00
Chairperson: -

Presentation Details

Presentation Type: Poster presentation
Title: Anomalous Reentrant Fractional Quantum Hall Effect at 5/2 in GaAs at Moderate Landau Level Mixing
Abstract: The fractional quantum Hall effect at 5/2 state has been experimentally found to host non-Abelian quasi-particles, which could be devised as qubits for topological quantum computation. In recent years, thermal Hall conductivity measurements at 5/2 have confirmed the particle-hole symmetric Pfaffian (PH-Pf) topological order, which is in contrast to the theoretical predictions of anti-Pfaffian orders. While earlier theoretical studies were mostly performed at Coulomb or small Landau level mixing regimes, in experimental systems the Landau level mixing strength is relatively high. At a moderate range of Landau level mixing strength, in accordance with the GaAs systems, we found a reentrant Anomalous phase (A-phase), which is quantized and well gapped in the thermodynamic limit and topologically distinct from the phase near pure Coulomb interaction. We further propose a wave function for this A-phase, that possesses high overlap and good matching of low-lying entanglement spectra. This work finds a possible resolution to the discrepancies between the theoretical predictions and experimental observations, and we believe our predicted wave function at the A-phase should possibly corroborate the experimentally found topological order.

Presenter

Dr Sudipto Das
Budapest University of Technology and Economics | Hungary

Authors

1. SUDIPTO DAS | Indian Institute of Technology Kharagpur, West Bengal, Indian
2. Sahana Das | Indian Institute of Technology Kharagpur, West Bengal, Indian
3. Sudhansu S. Mandal | Indian Institute of Technology Kharagpur, West Bengal, Indian