Composite Fermion Mass

Abstract

Composite fermions (CFs), exotic quasi-particles formed by pairing an electron and an even number of magnetic flux quanta emerge at high magnetic fields in an interacting electron system, and can explain phenomena such as the fractional quantum Hall state (FQHS) and other many-body phases. CFs possess an effective mass ($m_{CF}$) whose magnitude is inversely related to the most fundamental property of a FQHS, namely its energy gap. We present here experimental measurements of $m_{CF}$ in ultra-high quality two-dimensional electron systems confined to GaAs quantum wells of varying thickness. An advantage of measuring $m_{CF}$ over gap measurements is that mass values are insensitive to disorder and are therefore ideal for comparison with theoretical calculations, especially for high-order FQHS. Our data reveal that $m_{CF}$ increases with increasing well width, reflecting a decrease in the energy gap as the electron layer becomes thicker and the in-plane Coulomb energy softens. Comparing our measured masses with available theoretical results, we find significant quantitative discrepancies, highlighting that more rigorous and accurate calculations are needed to explain the experimental data.

References in corpus (19)

• Ultra-high quality two-dimensional electron systems
• Excitation gaps in fractional quantum Hall states: An exact diagonalization study
• Measurements of the density-dependent many-body electron mass in 2D GaAs/AlGaAs Heterostructures
• Composite Fermions Waltz to the Tune of a Wigner Crystal
• Transference of Transport Anisotropy to Composite Fermions
• Composite Fermions with Tunable Fermi Contour Anisotropy
• Composite Fermions and Landau Level Mixing in the Fractional Quantum Hall Effect
• Activation gaps for the fractional quantum Hall effect: realistic treatment of transverse thickness
• Strongly enhanced effective mass in dilute two-dimensional electron systems: System-independent origin
• Temperature dependent magnetotransport around $\nu$= 1/2 in ZnO heterostructures
• Fractional quantum Hall effect energy gap: role of electron layer thickness
• Particle-Hole Symmetry and the Fractional Quantum Hall Effect in the Lowest Landau Level
• Surprising robustness of particle-hole symmetry for composite fermion liquids
• Working principles of doping-well structures for high-mobility two-dimensional electron systems
• Bloch Ferromagnetism of Composite Fermions
• The effective electron mass in high-mobility SiGe/Si/SiGe quantum wells
• Precise Experimental Test of the Luttinger Theorem and Particle-Hole Symmetry for a Strongly Correlated Fermionic System
• Cyclotron Orbits of Composite Fermions in the Fractional Quantum Hall Regime
• Composite fermion mass enhancement and particle-hole symmetry of fractional quantum Hall states in the lowest Landau level under realistic conditions

Cited by in corpus (5)

• Integer and fractional quantum anomalous Hall effects in pentalayer graphene
• Oscillations in the radiative damping of plasma resonances in a gated disk of 2D electron gas
• Edge-driven transition between extended quantum anomalous Hall crystal and fractional Chern insulator in rhombohedral graphene multilayers
• Large composite fermion effective mass at filling factor 5/2
• Near-field heat transfer and drag resistance in bilayers of composite fermions