Controllable Quantum Point Junction on the Surface of an Antiferromagnetic Topological Insulator

Depiction of a magnetic domain wall (a) and a step edge (b) on the surface of an antiferromagnetic (alternating black arrows) topological insulator creating quantum wires that can intersect (c) to form a stable quantum point junction (QPJ).

Invention Summary:

Surface and edge-state engineering of topological materials offers great promise for future electronic devices, in particular, the topologically-protected chiral (one-way) or helical (two-way) edge states provide dissipationless “quantum wires" with potential applications in sensor, low-power electronics, and quantum information technologies. A crucial part of engineering such wires requires robust and tunable junctions between edge states to fully control the mixing and interference of edge-state wave functions.

Rutgers researchers proposed to achieve this control by using an antiferromagnetic topological insulator that supports two distinct types of gapless unidirectional channels, one from antiferromagnetic domain walls and the other from single-height steps. Their distinct geometric nature allows them to intersect robustly to form quantum point junctions, and their presence at the surface makes them subject to control by magnetic and electrostatic local probes.

A model has been developed to simulate the idealized situation. Prospects for realizing such junctions are encouraged by recent material candidate proposals, potentially leading to exciting applications in quantum computing and sensing.


  • A completely tunable quantum point junction that is thermodynamically stable with essentially lossless transport properties.

Market Applications:

  • Electron interferometry
  • Low-power electronics
  • Quantum computing and sensing

Intellectual Property & Development Status: Patent pending. Available for licensing and/or research collaboration.


Publication: Nature Communications 12, 3998 (2021)

Patent Information: