Fractional Quantum Hall States in a Ge Quantum Well

Abstract

Measurements of the Hall and dissipative conductivity of a strained Ge quantum well on a SiGe/(001)Si substrate in the quantum Hall regime are reported. We find quantum Hall states in the Composite Fermion family and a precursor signal at filling fraction $\nu =5/2$. We analyse the results in terms of thermally activated quantum tunneling of carriers from one internal edge state to another across saddle points in the long range impurity potential. This shows that the gaps for different filling fractions closely follow the dependence predicted by theory. We also find that the estimates of the separation of the edge states at the saddle are in line with the expectations of an electrostatic model in the lowest spin-polarised Landau level (LL), but not in the spin-reversed LL where the density of quasiparticle states is not high enough to accommodate the carriers required.

5 pages, 4 figures, supplemental material 2 pages, 1 figure

References in corpus (5)

• Fractional quantum Hall effect in CdTe
• Spinless composite fermions in an ultra-high quality strained Ge quantum well
• Enhanced bulk-edge Coulomb coupling in Fractional Fabry-Perot interferometers
• Model for Dissipative Conductance in Fractional Quantum Hall States
• Exploration of the Limits to Mobility in Two-Dimensional Hole Systems in GaAs/AlGaAs Quantum Wells

Cited by in corpus (9)

• The germanium quantum information route
• Ultra-high quality two-dimensional electron systems
• Lightly-strained germanium quantum wells with hole mobility exceeding one million
• Effective g factor of low-density two-dimensional holes in a Ge quantum well
• Majorana bound states in germanium Josephson junctions via phase control
• Effective g factor of 2D holes in strained Ge quantum wells
• High transparency induced superconductivity in field effect two-dimensional electron gases in undoped InAs/AlGaSb surface quantum wells
• Impact of in-situ controlled disorder screening on fractional quantum Hall effects and composite-fermion transport
• Exploring Quantum Hall Physics at Ultra-Low Temperatures and at High Pressures