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Updated: Mar 1, 2026
10:26
Fabrication and Characterization of Superconducting Resonators
Published on: May 21, 2016
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An on/off Berry phase switch in circular graphene resonators.
Fereshte Ghahari1,2, Daniel Walkup1,2, Christopher Gutiérrez1,2
1Center for Nanoscale Science and Technology, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA.
Science (New York, N.Y.)
|May 27, 2017
Summary
Researchers discovered a Berry phase in graphene that causes a sudden energy increase in quantum states. This phase, switchable with a magnetic field, could lead to new graphene optoelectronic devices.
Area of Science:
- Quantum Physics
- Condensed Matter Physics
- Materials Science
Background:
- The Berry phase is a quantum mechanical phenomenon where a quantum state's phase shifts after parameter cycling.
- Traditionally, Berry phases are observed via interference experiments.
Purpose of the Study:
- To demonstrate a novel Berry phase-induced spectroscopic feature in graphene.
- To explore the potential of Berry phases for optoelectronic applications.
Main Methods:
- Investigated circular graphene p-n junction resonators.
- Applied a critical magnetic field to induce and observe the Berry phase effect.
Main Results:
- Observed a sudden, significant increase in the energy of angular-momentum states.
- Attributed this to a π Berry phase linked to Dirac fermions' topological properties.
- Demonstrated the Berry phase can be switched on/off with a ~10 millitesla magnetic field.
Conclusions:
- The study reveals an unusual Berry phase-induced spectroscopic behavior in graphene.
- This controllable Berry phase offers potential for developing novel graphene-based optoelectronic devices.
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