Extracting net current from an upstream neutral mode in the fractional quantum Hall regime

Abstract

Upstream neutral modes, counter propagating to charge modes and carrying energy without net charge, had been predicted to exist in some of the fractional quantum Hall states and were recently observed via noise measurements. Understanding such modes will assist in identifying the wavefunction of these states, as well as shedding light on the role of Coulomb interactions within edge modes. In this work, performed mainly in the nu=2/3 state, we placed a quantum dot a few micrometers upstream of an ohmic contact, which served as a neutral modes source. We showed the neutral modes heat the input of the dot, causing a net thermo-electric current to flow through it. Heating of the electrons led to a decay of the neutral mode, manifested in the vanishing of the thermo-electric current at T>110mK. This setup provides a straightforward method to investigate upstream neutral modes without turning to the more cumbersome noise measurements.

35 pages, 5 figures

References in corpus (4)

• Particle-Hole Symmetry and the $\nu =5/2$ Quantum Hall State
• Observation of neutral modes in the fractional quantum Hall regime
• Thermoelectric probe for neutral edge modes in the fractional quantum Hall regime
• Dynamics of edge Majorana fermions in $\nu =\frac{5}{2}$ fractional quantum Hall effects

Cited by in corpus (7)

• Non-Equilibrated Counter Propagating Edge Modes in the Fractional Quantum Hall Regime
• Transmission of heat modes across a potential barrier
• Coulomb blockade with neutral modes
• Thermoelectric properties of Coulomb-blockaded fractional quantum Hall islands
• Statistics of energy dissipation in a quantum dot operating in the cotunneling regime
• Unexpected tunneling current from downstream neutral modes
• Thermopower in the Coulomb blockade regime for Laughlin quantum dots