Tunnel transport and interlayer excitons in bilayer fractional quantum Hall systems

Abstract

In a bilayer system consisting of a composite-fermion Fermi sea in each layer, the tunnel current is exponentially suppressed at zero bias, followed by a strong peak at a finite bias voltage $V_{\max }$. This behavior, which is qualitatively different from that observed for the electron Fermi sea, provides fundamental insight into the strongly correlated non-Fermi liquid nature of the CF Fermi sea and, in particular, offers a window into the short-distance high-energy physics of this state. We identify the exciton responsible for the peak current and provide a quantitative account of the value of $V_{\max }$. The excitonic attraction is shown to be quantitatively significant, and its variation accounts for the increase of $V_{\max }$ with the application of an in-plane magnetic field. We also estimate the critical Zeeman energy where transition occurs from a fully spin polarized composite fermion Fermi sea to a partially spin polarized one, carefully incorporating corrections due to finite width and Landau level mixing, and find it to be in satisfactory agreement with the Zeeman energy where a qualitative change has been observed for the onset bias voltage [Eisenstein et al., Phys. Rev. B 94, 125409 (2016)]. For fractional quantum Hall states, we predict a substantial discontinuous jump in $V_{\max }$ when the system undergoes a transition from a fully spin polarized state to a spin singlet or a partially spin polarized state.

14 pages, 14 figures

References in corpus (3)

• Spin Transition in the Half-Filled Landau Level
• Spin-Polarization of Composite Fermions and Particle-Hole Symmetry Breaking
• Spin and the Coulomb Gap in the Half-Filled Lowest Landau Level

Cited by in corpus (8)

• Crystallization in the Fractional Quantum Hall Regime Induced by Landau-level Mixing
• Fermi wave vector for the non-fully spin polarized composite-fermion Fermi sea
• Imaging anyons with scanning tunneling microscopy
• Effect of magnetization on the tunneling anomaly in compressible quantum Hall states
• Semiclassical theory of the tunneling anomaly in partially spin-polarized compressible quantum Hall states
• Interlayer Interactions and the Fermi Energy of Bilayer Composite Fermion Metals
• Tunneling density of states, correlation energy, and spin polarization in the fractional quantum Hall regime
• Spinless and spinful charge excitations in moiré Fractional Chern Insulators