Direct observation of composite fermions and their fully spin-polarized Fermi sea near $\nu =5/2$

Abstract

The enigmatic even-denominator fractional quantum Hall state at Landau level filling factor $\nu =5/2$ is arguably the most promising candidate for harboring Majorana quasi-particles with non-Abelian statistics and thus of potential use for topological quantum computing. The theoretical description of the $\nu =5/2$ state is generally believed to involve a topological p-wave pairing of fully spin-polarized composite fermions through their condensation into a non-Abelian Moore-Read Pfaffian state. There is, however, no direct and conclusive experimental evidence for the existence of composite fermions near $\nu =5/2$ or for an underlying fully spin-polarized Fermi sea. Here, we report the observation of composite fermions very near $\nu =5/2$ through geometric resonance measurements, and find that the measured Fermi wavevector provides direct demonstration of a Fermi sea with full spin polarization. This lends crucial credence to the model of $5/2$ fractional quantum Hall effect as a topological p-wave paired state of composite fermions.

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Cited by in corpus (23)

• Partial equilibration of integer and fractional edge channels in the thermal quantum Hall effect
• Comment on S. H. Simon, Interpretation of thermal conductance of the $\nu =5/2$ edge, arXiv:1801.09687
• Topological properties of multi-terminal superconducting nanostructures: effect of a continuous spectrum
• The sixteenfold way and the quantum Hall effect at half-integer filling factors
• Edge Probes of Topological Order
• Bloch Ferromagnetism of Composite Fermions
• Fractional Quantum Hall State at Filling Factor $\nu =1/4$ in Ultra-High-Quality GaAs 2D Hole Systems
• Bardeen-Cooper-Schrieffer pairing of composite fermions
• Precise Experimental Test of the Luttinger Theorem and Particle-Hole Symmetry for a Strongly Correlated Fermionic System
• Geometric Resonance of Four-Flux Composite Fermions
• Fractional quantum Hall effect at the filling factor $\nu =5/2$
• Competition of Pairing and Nematicity in the Two-Dimensional Electron Gas
• PH-Pfaffian order in a translationally and rotationally invariant system
• Weyl point immersed in a continuous spectrum: an example from superconducting nanostructures
• Identification of topological order in the fractional quantum Hall state at $\nu =1/4$
• Valley-tunable, even-denominator fractional quantum Hall state in the lowest Landau level of an anisotropic system
• Finite-thickness effect and spin polarization of the even-denominator fractional quantum Hall states
• Large composite fermion effective mass at filling factor 5/2
• Single-parameter variational wavefunctions for quantum Hall bilayers
• Short and Long Ranged Impurities in Fractional Quantum Hall Systems
• Exactly Solvable Hamiltonian for Non-Abelian Quasiparticles
• Edge Induced Topological Phase Transition of the Quantum Hall state at Half Filling
• Spin polarization of Quantum Hall states for filling factors 1 < v < 2 measured with microcavity polaritons