Observation of Inter-Valley Gap Anomaly of Two Dimensional electrons in Silicon

Abstract

We report here a systematic study of the energy gaps at the odd-integer quantum Hall states $\nu =3$ and 5 under tilted magnetic (B) fields in a high quality Si two-dimensional electron system. Out of the coincidence region, the valley splitting is independent of the in-plane B fields. However, the $\nu =3$ valley gap differs by about a factor of 3 (${\Delta }_v\sim$ 0.4K vs. 1.2K) at either side of the coincidence. More surprisingly, instead of reducing to zero, the energy gaps at $\nu =3$ and 5 rise rapidly when approaching the coincidence angles. We believe that such anomaly is related to strong coupling of the nearly degenerate Landau levels.

arXiv comment4 REVTEX pages, 4 figures

References in corpus (7)

• Exchange in silicon-based quantum computer architecture
• Resistance Spikes at Transitions between Quantum Hall Ferromagnets
• First-Order Phase Transition in a Quantum Hall Ferromagnet
• Resistance spikes and domain wall loops in Ising quantum Hall ferromagnets
• Quantum Hall Ferromagnetism in a Two-Dimensional Electron System
• Strong enhancement of the valley splitting in a 2D electron system in silicon
• Longitudinal conductivity in Si/SiGe heterostructure at integer filling factors

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• Valley splitting of Si/SiGe heterostructures in tilted magnetic fields
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• Interplay of Lorentz-Berry forces in position-momentum spaces for valley-dependent impurity scattering in alpha-T3 lattices
• Robust Quantum Hall Ferromagnetism near a Gate-Tuned ν = 1 Landau Level Crossing
• Electronic Transport Properties of the Ising Quantum Hall Ferromagnet in a Si Quantum Well
• Dependence of persistent gaps at Landau level crossings on relative spin
• Probing Quantum Hall Pseudospin Ferromagnet by Resistively Detected NMR
• Density-controlled quantum Hall ferromagnetic transition in a two-dimensional hole system
• Magnetic-field dependence of valley splitting for Si quantum wells grown on tilted SiGe substrates
• Observation of an in-plane magnetic-field-driven phase transition in a quantum Hall system with SU(4) symmetry
• Valley splitting in a Si/SiGe quantum point contact
• Spin-dependent edge-channel transport in a Si/SiGe quantum Hall system