Exciton Condensation in Quantum Hall Bilayers at Total Filling ${\nu }_T=5$

Abstract

We study the coupled quantum Hall bilayers each at half-filled first excited Landau levels with varying the layer distance. Based on numerical exact diagonalization on torus, we identify two distinct phases separated by a critical layer distance $d_c$. From $d_c$ to infinite layer distance, the topological phase is smoothly connected to a direct tensor product of two Moore-Read states, while the interlayer coherence emerges at $d<d_c$ characterized by the $xy$ easy-plane ferromagnetic energy spectra, gapless pseudospin excitations and the finite exciton superfluid stiffness, corresponding to the exciton superfluid state. More interestingly, the results of the ground state fidelity, the evolution of energy spectra, and the superfluid stiffness indicate a possible continuous transition. Theoretically it can be interpreted as a topological phase transition which simultaneously changes the topology of ground state and breaks symmetry, providing an interesting example of transitions beyond Landau paradigm.

6 pages, 4 figures

References in corpus (12)

• Non-Abelian Anyons and Topological Quantum Computation
• "Deconfined" quantum critical points
• Quantum Spin Hall Effect and Topologically Invariant Chern Numbers
• Fractional quantum Hall effect in the absence of Landau levels
• Anyons and the quantum Hall effect - a pedagogical review
• Tunable Fractional Quantum Hall Phases in Bilayer Graphene
• Paired composite fermion phase of quantum Hall bilayers at ν= 1/2 + 1/2
• Trial Wavefunctions for ν= 1/2 + 1/2 Quantum Hall Bilayers
• Composite fermion duality for half-filled multicomponent Landau Levels
• Intrinsic gap and exciton condensation in the nu_T=1 bilayer system
• Finite-momentum condensate of magnetic excitons in a bilayer quantum Hall system
• Partial filled Landau Level at even denominator, a vortex metal with Berry phase

Cited by in corpus (4)

• Excitonic Condensate in Flat Valence and Conduction Bands of Opposite Chirality
• Non-Abelian spin Hall insulator
• Interlayer exciton condensates between second Landau level orbitals in double bilayer graphene
• Role of the compensating current in the weak Josphson coupling regime: An extended study on excitonic Josephson junctions