|Title:||Density-controlled quantum Hall ferromagnetic transition in a two-dimensional hole system||Authors:||T. M. Lu
L. A. Tracy
S. –H. Huang
Y. –H Su
|Issue Date:||2017||Journal Volume:||7||Start page/Pages:||3157||Source:||Scientific Reports||Abstract:||
Quantum Hall ferromagnetic transitions are typically achieved by increasing the Zeeman energy through in-situ sample rotation, while transitions in systems with pseudo-spin indices can be induced by gate control. We report here a gate-controlled quantum Hall ferromagnetic transition between two real spin states in a conventional two-dimensional system without any in-plane magnetic field. We show that the ratio of the Zeeman splitting to the cyclotron gap in a Ge two-dimensional hole system increases with decreasing density owing to inter-carrier interactions. Below a critical density of ~2.4 × 1010 cm-2, this ratio grows greater than 1, resulting in a ferromagnetic ground state at filling factor ν = 2. At the critical density, a resistance peak due to the formation of microscopic domains of opposite spin orientations is observed. Such gate-controlled spin-polarizations in the quantum Hall regime opens the door to realizing Majorana modes using two-dimensional systems in conventional, low-spin-orbit-coupling semiconductors. © 2017 The Author(s).
|Appears in Collections:||電機工程學系|
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