Quantum Anomalous Parity Hall Effect in Magnetically Disordered Topological Insulator Films

Area of Science:

• Condensed matter physics
• Materials science
• Quantum phenomena

Background:

• Magnetically doped topological insulators exhibit quantum anomalous Hall (QAH) effects with chiral edge states when magnetic moments are aligned.
• Demagnetization in these systems introduces disorder, altering their electronic properties.

Purpose of the Study:

• To investigate the emergence of new topological phases in demagnetized topological insulators.
• To explore the creation and manipulation of Majorana zero modes using electrical means.

Main Methods:

• Theoretical modeling of magnetically doped thin-film topological insulators.
• Analysis of edge states under conditions of disordered magnetic moments.
• Incorporation of superconductivity and gate-induced symmetry breaking.

Main Results:

• Identification of a "quantum anomalous parity Hall" (QAPH) phase in demagnetized systems, characterized by helical edge modes protected by reflection symmetry.
• Demonstration that superconductivity combined with selective gate-induced symmetry breaking allows for the creation and manipulation of Majorana zero modes.
• Achieved electrical control of Majorana zero modes at zero applied magnetic field.

Conclusions:

• Disordered magnetic topological insulators can host novel topological phases beyond the standard QAH effect.
• The QAPH phase provides a platform for realizing topological superconductivity.
• Electrical control of Majorana zero modes in these systems opens pathways for fault-tolerant quantum computing.