Quantum Hall effect of the topological insulator state of cadmium arsenide in Corbino geometry
Abstract
The surfaces of a three-dimensional topological insulator each host a single Dirac fermion, which, in a strong magnetic field, contribute to the transverse conductance in integer-and-a-half multiples of the conductance quantum. The direct observation of this extra half integer, the hallmark of the two-dimensional Dirac state, is usually thwarted by the fermion doubling theorem—top and bottom surfaces are not measured independently. Here, we employ a Corbino measurement geometry in which a current, induced by an ac magnetic field, is driven around the ring, as a complementary measurement to the conventional Hall bar geometry. As the device enters the quantum Hall regime, the transverse voltage reaches a series of plateaus when the current is carried by the incompressible bulk states. We compare the results with the corresponding Hall bar measurements.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Jun 28, 2021
- Source ID
- 10.1063/5.0056357
Entities
People
- Arman Rashidi
- Binghao Guo
- Chen Shang
- David A Kealhofer
- John E. Bowers
- Luca Galletti
- Manik Goyal
- Susanne Stemmer
- Yuntian Li
Organizations
- Army Research Office
- National Science Foundation
- United States Department of Defense