Novel Bulk Quantum Hall Effect in Nanostructured TaP Macroscopic Crystals.

Area of Science:

• Condensed Matter Physics
• Materials Science
• Quantum Phenomena

Background:

• Bulk quantum Hall effect (QHE) is a rare phenomenon in macroscopic materials, despite its significance for coherent electron transport.
• The two-dimensional (2D) QHE is well-established, but its bulk counterpart remains elusive in real-world applications.

Purpose of the Study:

• To report the observation of bulk QHE in macroscopic, nanostructured tantalum phosphide (TaP) crystals.
• To elucidate the mechanism behind the observed bulk QHE through microstructure engineering.

Main Methods:

• Fabrication of millimeter-sized TaP crystals with nanometer-scale lamellar structures.
• Experimental measurement of transverse and vertical resistivity under magnetic fields.
• Analysis of electron transport phenomena influenced by Landau cyclotron motion and modulated potentials.

Main Results:

• Observation of simultaneous quantum plateaus in both transverse resistivity (ρxy) and vertical resistivity (ρzz).
• Demonstration of bulk QHE in macroscopic TaP crystals, attributed to the synergetic effects of magnetic field and nanostructure.
• Evidence of fixed edge states along both B-perpendicular and B-parallel directions, mimicking stacked 2D-QHE layers.

Conclusions:

• Microstructure engineering is a viable strategy to induce coherent electron transport and novel quantum phenomena in bulk materials.
• The observed bulk QHE in TaP crystals opens new avenues for exploring quantum effects in macroscopic systems.
• This work highlights the potential for creating advanced materials with tailored quantum properties.